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

Author

Alois P. Heinz, Jul 25 2018

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 16..469

Crossrefs

Column k=8 of A097592.

Programs

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);