OFFSET
0,2
COMMENTS
Also the number of ascending runs of length n+7 in the permutations of [2n+7].
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..300
FORMULA
MAPLE
a:= proc(n) option remember; `if`(n<2, 1+15*n, 2*(n+3)*(2*n+7)*
(n^3+16*n^2+72*n+71)*a(n-1)/((n+9)*(n^3+13*n^2+43*n+14)))
end:
seq(a(n), n=0..25);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Oct 16 2013
STATUS
approved