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A317289
Number of permutations of [n] with exactly nine increasing runs of even length.
2
2404879675441, 208031951035452, 10539887638301128, 438391470941407244, 16755405367563104497, 607314204208297961718, 21247637795898419646167, 729013114914519439841722, 24775048055015061709737839, 838857400014414535124226202, 28428368151331776174951956983
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OFFSET
18,1
LINKS
Alois P. Heinz,
Table of n, a(n) for n = 18..468
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, 10)
end:
a:= n-> coeff(b(n, 0$2), x, 9):
seq(a(n), n=18..30);
CROSSREFS
Column k=9 of
A097592
.
Sequence in context:
A321708
A077304
A034658
*
A361935
A136174
A233496
Adjacent sequences:
A317286
A317287
A317288
*
A317290
A317291
A317292
KEYWORD
nonn
AUTHOR
Alois P. Heinz
, Jul 25 2018
STATUS
approved
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Last modified April 18 09:47 EDT 2024. Contains 371779 sequences. (Running on oeis4.)