Combinatorics on words

    Programs and datas for papers on combinatorics on words can be found here.
  1. On some interesting ternary formulas. Pascal Ochem and Matthieu Rosenfeld. WORDS 2017.
  2. Avoidability of formulas with two variables. Pascal Ochem and Matthieu Rosenfeld. DLT 2016.
  3. A short proof that shuffle squares are 7-avoidable. Guillaume Guegan and Pascal Ochem. Theor. Informatics Appl. 50(1) (2016), 101-103.
  4. Doubled patterns are 3-avoidable. Pascal Ochem. Electron. J. Comb. 23(1) (2016), #P1.19.
  5. Characterization of some binary words with few squares. Golnaz Badkobeh and Pascal Ochem. Theor. Comput. Sci. 588 (2015), 73-80.
  6. Application of entropy compression in pattern avoidance. Pascal Ochem and Alexandre Pinlou. Electron. J. Comb. 21(2) (2014), #RP2.7.
  7. Binary patterns in binary cube-free words: avoidability and growth. Robert Mercas, Pascal Ochem, Alexey Samsonov, and Arseny M. Shur. Theor. Informatics Appl. 48(4) (2014), 369-389.
  8. More on square-free words obtained from prefixes by permutations. Pascal Ochem. Fundamenta Informaticae 132 (2014), 1-4.
  9. Repetition thresholds for subdivided graphs and trees. Pascal Ochem and Elise Vaslet. Theor. Informatics Appl. 46(1) (2012), 123-130.
  10. Thue choosability of trees. Francesca Fiorenzi, Pascal Ochem, Patrice Ossona de Mendez, and Xuding Zhu. Disc. Appl. Math. 159(17) (2011), 2045-2049.
  11. Bounds for the generalized repetition threshold. Francesca Fiorenzi, Pascal Ochem, and Elise Vaslet. Theor. Comput. Sci. 412 (2011), 2955-2963.
  12. On maximal repetitions of arbitrary exponent. Roman Kolpakov, Gregory Kucherov, and Pascal Ochem. Inform. Process. Lett. 110(7) (2010), 252-256.
  13. Binary words avoiding the pattern AABBCABBA. Pascal Ochem. Theor. Informatics Appl. 44 (1) (2010), 151-158.
  14. Minimum frequencies of occurrences of squares and letters in infinite words. Pascal Ochem and Michael Rao. Mons Days of Theoretical Computer Science. Mons, August 27 - 30 2008
  15. Unequal letter frequencies in ternary square-free words. Pascal Ochem. WORDS 2007. Marseille, September 17-21 2007
  16. Avoiding approximate squares. Pascal Ochem, Narad Rampersad, and Jeffrey Shallit. IJFCS 19 (3) (2008), 633-648.
  17. Dejean's conjecture and letter frequency. Jeremie Chalopin and Pascal Ochem. Mons Days of Theoretical Computer Science. Rennes, August 30 - September 2 2006 Theor. Informatics Appl. 42 (3) (2008), 477-480.
  18. Upper bound on the number of ternary square-free words. Pascal Ochem and Tony Reix. Workshop on Words and Automata. St Petersburg, June 7 2006
  19. Letter frequency in infinite repetition-free words. Pascal Ochem. WORDS 2005. Montreal, September 13-17 2005. Theor. Comput. Sci. 380 (2007), 388-392.
  20. A generator of morphisms for infinite words. Pascal Ochem. Word avoidability, complexity and morphisms. Turku, July 17 2004. Theor. Informatics Appl. 40 (2006), 427-441.
  21. A generalization of repetition threshold. Lucian Ilie, Pascal Ochem, and Jeffrey Shallit. MFCS 2004. Prague, August 22-27 2004. Theor. Comput. Sci. 345 (2005), 359-369.
  22. How many square occurrences must a binary sequence contain ? Gregory Kucherov, Pascal Ochem, and Michael Rao. Electron. J. Comb. 10(1) (2003), #R12.
  23. Graph theory

  24. 2-subcoloring is NP-complete for planar comparability graphs. Pascal Ochem. Inform. Process. Lett. 128 (2017), 46-48.
  25. Oriented, 2-edge-colored, and 2-vertex-colored homomorphisms. Nazanin Movarraei and Pascal Ochem. Inform. Process. Lett. 123 (2017), 42-46.
  26. Exponential domination in subcubic graphs. Stephane Bessy, Pascal Ochem, and Dieter Rautenbach. Electron. J. Comb. 23(4) (2016), #P4.42.
  27. The complexity of partitioning into disjoint cliques and a triangle-free graph. Marin Bougeret and Pascal Ochem. Disc. Appl. Math. 217(3) (2017), 438-445.
  28. Bounds on the exponential domination number. Stephane Bessy, Pascal Ochem, and Dieter Rautenbach. Discrete Math. 340(3) (2017), 494-503.
  29. Homomorphisms of 2-edge-colored triangle-free planar graphs. Pascal Ochem, Alexandre Pinlou, and Sagnik Sen. J. Graph Theory 85(1) (2017), 258-277.
  30. Islands in graphs on surfaces. Louis Esperet and Pascal Ochem. SIAM Journal on Discrete Mathematics 30(1) (2016), 206-219.
  31. On interval representations of graphs. Aquiles Braga De Queiroz, Valentin Garnero, and Pascal Ochem. Disc. Appl. Math. 202 (2016), 30-36.
  32. Complexity dichotomy for oriented homomorphism of planar graphs with large girth. Guillaume Guegan and Pascal Ochem. Theor. Comput. Sci. 596 (2015), 142-148.
  33. Near-colorings: non-colorable graphs and NP-completeness. Mickael Montassier and Pascal Ochem. Electron. J. Comb. 22(1) (2015), #P1.57.
  34. The maximum clique problem in multiple interval graphs. Mathew C. Francis, Daniel Gonçalves, and Pascal Ochem. WG'2012, 57-68. Algorithmica 71(4) (2015), 812-836.
  35. Vertex-partitions of graphs into cographs and stars. Paul Dorbec, Mickael Montassier, and Pascal Ochem. J. Graph Theory 75(1) (2014), 75-90.
  36. Strong edge-colouring and induced matchings. Herve Hocquard, Pascal Ochem, and Petru Valicov. Inform. Process. Lett. 113(19-21) (2013), 836-843.
  37. A complexity dichotomy for the coloring of sparse graphs. Louis Esperet, Mickael Montassier, Pascal Ochem, and Alexandre Pinlou. J. Graph Theory 73(1) (2013), 85-102.
  38. Locally identifying coloring of graphs Louis Esperet, Sylvain Gravier, Mickael Montassier, Pascal Ochem, and Aline Parreau. Electron. J. Comb. 19(2) (2012), #P40.
  39. Oriented coloring of triangle-free planar graphs and 2-outerplanar graphs. Pascal Ochem and Alexandre Pinlou. LAGOS 2011, Bariloche, Argentina, March 28 - April 1st 2011. Graphs and Combinatorics 30(2) (2014), 439-453.
  40. Homomorphisms of 2-edge-colored graphs. Amanda Montejano, Pascal Ochem, Alexandre Pinlou, Andre Raspaud, and Eric Sopena. Disc. App. Math. 158(12) (2010), 1365-1379.
  41. Vertex decompositions of sparse graphs into an edgeless subgraph and a subgraph of maximum degree at most k. Oleg V. Borodin, Anna O. Ivanova, Mickael Montassier, Pascal Ochem, and Andre Raspaud. J. Graph Theory 65(2) (2010), 83-93.
  42. On star and caterpillar arboricity. Daniel Gonçalves, Pascal Ochem. Discrete Math. 309(11) (2009), 3694-3702.
  43. On induced-universal graphs for the class of bounded-degree graphs. Louis Esperet, Arnaud Labourel, and Pascal Ochem. Inform. Process. Lett. 108(5) (2008), 255-260.
  44. Strong oriented chromatic number of planar graphs without short cycles. Mickael Montassier, Pascal Ochem, and Alexandre Pinlou. DMTCS 10(1) (2008).
  45. On the oriented chromatic index of oriented graphs. Pascal Ochem, Alexandre Pinlou, and Eric Sopena. J. Graph Theory 57(4) (2008), 313-332.
  46. On circle graphs with girth at least five. Louis Esperet, Pascal Ochem. EuroComb 2007. Seville, September 11-15 2007. ENDM 29 (2007), 129-133. Discrete Math. 309(8) (2009), 2217-2222.
  47. Oriented colorings of partial 2-trees. Pascal Ochem, Alexandre Pinlou. EuroComb 2007. Seville, September 11-15 2007. ENDM 29 (2007), 195-199. Inform. Process. Lett. 108(2) (2008), 82-86.
  48. Planar graphs have 1-string representations. Jeremie Chalopin, Daniel Gonçalves, and Pascal Ochem. Discrete and Computational Geometry 43(3) (2010), 626-647.
  49. Oriented colorings of 2-outerplanar graphs. Louis Esperet, Pascal Ochem. Inform. Process. Lett. 101(5) (2006), 215-219.
  50. Negative results on acyclic improper colorings. Pascal Ochem. EuroComb 2005. Berlin, September 5-9 2005. DMTCS Conference Volume AE (2005), 357-362.
  51. On the acyclic choosability of graphs. Mickael Montassier, Pascal Ochem, and Andre Raspaud. Graph Theory 2004. Paris, July 5-9 2004 J. Graph Theory 51(4) (2006), 281-300.
  52. Oriented colorings of triangle-free planar graphs. Pascal Ochem. Inform. Process. Lett. 92(2) (2004), 71-76.
  53. On the interval number of special graphs. Jozsef Balogh, Pascal Ochem, and Andras Pluhar. J. Graph Theory 46(4) (2004), 241-253.
  54. Odd perfect numbers

    Programs and datas for odd perfect numbers can be found here.
  55. Another remark on the radical of an odd perfect number. Pascal Ochem and Michael Rao. The Fibonacci Quarterly 52(3) (2014), 215-217.
  56. On the number of prime factors of an odd perfect number. Pascal Ochem and Michael Rao. Math. Comp. 83 (2014), 2435-2439.
  57. Odd perfect numbers are greater than 101500. Pascal Ochem and Michael Rao. Math. Comp. 81 (2012), 1869-1877.
  58. Sieve methods for odd perfect numbers. S. Adam Fletcher, Pace P. Nielsen, and Pascal Ochem. Math. Comp. 81 (2012), 1753-1776.
  59. Submitted manuscripts

  60. Avoidability of circular formulas. Guilhem Gamard, Pascal Ochem, Gwenael Richomme, and Patrice Seebold.
  61. On repetition thresholds of caterpillars and trees of bounded degree. Borut Luzar, Pascal Ochem, Alexandre Pinlou.
  62. Ph.D. thesis (in English)

    Graph coloring and combinatorics on words.