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 A279559 Number of length n inversion sequences avoiding the patterns 010 and 120. 22
 1, 1, 2, 5, 15, 52, 201, 845, 3801, 18089, 90316, 470010, 2536077, 14127741, 80966690, 475979359, 2863157581, 17585971037, 110095460224, 701418693025, 4541497543092, 29847982448766, 198913925919741, 1342890255133042, 9176456969273844, 63422002415068463 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS A length n inversion sequence e_1e_2...e_n is a sequence of integers where 0 <= e_i <= i-1. The term a(n) counts those length n inversion sequences with no entries e_i, e_j, e_k (where i= e_k. This is the same as the set of length n inversion sequences avoiding 010 and 120. LINKS Megan A. Martinez, Carla D. Savage, Patterns in Inversion Sequences II: Inversion Sequences Avoiding Triples of Relations, arXiv:1609.08106 [math.CO], 2016. Chunyan Yan, Zhicong Lin, Inversion sequences avoiding pairs of patterns, arXiv:1912.03674 [math.CO], 2019. EXAMPLE The length 4 inversion sequences avoiding (010, 120) are 0000, 0001, 0002, 0003, 0011, 0012, 0013, 0021, 0022, 0023, 0111, 0112, 0113, 0122, 0123. CROSSREFS Cf. A000108, A263777, A263778, A263779, A263780, A279551, A279552, A279553, A279554, A279555, A279556, A279557, A279558, A279560, A279561, A279562, A279563, A279564, A279565, A279566, A279567, A279568, A279569, A279570, A279571, A279572, A279573. Sequence in context: A279558 A224071 A202062 * A056272 A140980 A287254 Adjacent sequences:  A279556 A279557 A279558 * A279560 A279561 A279562 KEYWORD nonn AUTHOR Megan A. Martinez, Jan 17 2017 EXTENSIONS a(10)-a(25) from Alois P. Heinz, Feb 22 2017 STATUS approved

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Last modified April 6 11:38 EDT 2020. Contains 333273 sequences. (Running on oeis4.)