OFFSET
0,2
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..350
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
PROG
(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)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Mar 11 2007
STATUS
approved