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A317287 Number of permutations of [n] with exactly seven increasing runs of even length. 2
199360981, 11190963430, 378291607803, 11014069796526, 305943708449074, 8211684416287224, 215906484804391566, 5654455021954104792, 148657867362265421769, 3937297418900898841450, 105451222548147683308147, 2864250745636538809593802, 79027581972356621300952774 (list; graph; refs; listen; history; text; internal format)
OFFSET

14,1

LINKS

Alois P. Heinz, Table of n, a(n) for n = 14..469

MAPLE

b:= proc(u, o, t) option remember; series(`if`(u+o=0, x^t,

      add(b(u+j-1, o-j, irem(t+1, 2)), j=1..o)+

      add(b(u-j, o+j-1, 0)*x^t, j=1..u)), x, 8)

    end:

a:= n-> coeff(b(n, 0$2), x, 7):

seq(a(n), n=14..30);

CROSSREFS

Column k=7 of A097592.

Sequence in context: A251514 A268844 A015368 * A132205 A015427 A078249

Adjacent sequences:  A317284 A317285 A317286 * A317288 A317289 A317290

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Jul 25 2018

STATUS

approved

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Last modified November 18 07:22 EST 2019. Contains 329252 sequences. (Running on oeis4.)