A205774 G.f. satisfies: A(x) = 1/Product_{n>=1} (1 - x^n*A(x^n)^3).

1, 1, 5, 27, 177, 1245, 9399, 73659, 595510, 4923724, 41451675, 354071010, 3061018302, 26732084764, 235476740731, 2089770720125, 18666863392846, 167697751329817, 1514206777182411, 13734387733516323, 125083419013852945, 1143367086845429280

Offset

0,3

Links

Table of n, a(n) for n=0..21.

Example

 G.f.: A(x) = 1 + x + 5*x^2 + 27*x^3 + 177*x^4 + 1245*x^5 +...
where
A(x) = 1/((1 - x*A(x)^3) * (1 - x^2*A(x^2)^3) * (1 - x^3*A(x^3)^3) *...).

Prog

 (PARI) {a(n)=local(A=1+x); for(i=1, n, A=1/prod(k=1, n, (1-x^k*subst(A, x, x^k+x*O(x^n))^3))); polcoeff(A, n)}

Crossrefs

Cf. A050383, A196192, A205775, A196191.

Sequence in context: A185622 A225309 A231091 * A367048 A326094 A232683

Adjacent sequences: A205771 A205772 A205773 * A205775 A205776 A205777

Keyword

nonn

Author

Paul D. Hanna, Jan 31 2012

Status

approved