A317288 Number of permutations of [n] with exactly eight increasing runs of even length.

19391512145, 1367267690953, 57188581537971, 2006576231088264, 65823539327956911, 2066450841399035025, 63056350327027739274, 1900463594609383889937, 57088794679037177345346, 1717519261928956311195227, 51966007918370324842446184, 1586467824560962829102119877

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