OFFSET
1,2
COMMENTS
a(n) = A324958(n,n-1) for n >= 1.
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 1..300
FORMULA
a(n) ~ n! * c * 5^(5*n) / (2^(8*n) * n^2), where c = 1/(5*Pi*sqrt(10*log(5/4))) = 0.04261749831824651172873387091554100360007169830546206828545398795767677148... - Vaclav Kotesovec, Oct 30 2019, updated Mar 17 2024
MATHEMATICA
Table[If[n==1, 1, Coefficient[Expand[Product[(n + (2*n+k)*y + n*y^2), {k, 0, n-2}]], y^(n-1)]], {n, 1, 20}] (* Vaclav Kotesovec, Oct 30 2019 *)
PROG
(PARI) {a(n) = polcoeff( prod(k=0, n-2, n + (2*n+k)*y + n*y^2 +y*O(y^n)), n-1, y)}
for(n=1, 25, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Mar 20 2019
STATUS
approved