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A317288 Number of permutations of [n] with exactly eight increasing runs of even length. 2
19391512145, 1367267690953, 57188581537971, 2006576231088264, 65823539327956911, 2066450841399035025, 63056350327027739274, 1900463594609383889937, 57088794679037177345346, 1717519261928956311195227, 51966007918370324842446184, 1586467824560962829102119877 (list; graph; refs; listen; history; text; internal format)
OFFSET

16,1

LINKS

Alois P. Heinz, Table of n, a(n) for n = 16..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, 9)

    end:

a:= n-> coeff(b(n, 0$2), x, 8):

seq(a(n), n=16..30);

CROSSREFS

Column k=8 of A097592.

Sequence in context: A273186 A185932 A262533 * A234397 A234194 A118466

Adjacent sequences:  A317285 A317286 A317287 * A317289 A317290 A317291

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Jul 25 2018

STATUS

approved

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Last modified May 23 10:05 EDT 2022. Contains 353975 sequences. (Running on oeis4.)