A128575 Row 5 of table A128570.
1, 6, 84, 1638, 38976, 1068480, 32716992, 1098069504, 39896236800, 1555603999488, 64678765165056, 2853714891138048, 133101200708356608, 6542154022577467392, 337978986519657627648, 18310837206705702672384
Offset: 0
Keywords
Links
- Vaclav Kotesovec, Table of n, a(n) for n = 0..350
Crossrefs
Programs
-
PARI
{a(n)=local(A=1+(n+6)*x);for(j=0,n,A=1+(n+6-j)*x*A^2 +x*O(x^n)); polcoeff(A,n)}
Formula
G.f.: A(x) = 1 + 6x*R(x,6)^2, where R(x,6) = 1 + 7*x*R(x,7)^2, R(x,7) = 1 + 8*x*R(x,8)^2, ..., R(x,n) = 1 + (n+1)*x*R(x,n+1)^2, ... and R(x,n) is the g.f. of row n of table A128570.
a(n) ~ 128*n^5*A128318(n)/3645. - Vaclav Kotesovec, Mar 19 2016