A203507 G.f.: Product_{n>=0} 1/(1-a(n)*x^(n+1))^3 = Sum_{n>=0} a(n)*x^n.

1, 3, 15, 82, 504, 3198, 21592, 147570, 1045221, 7464052, 54549804, 400487997, 2990765270, 22396990002, 169881957174, 1291189065086, 9910770901971, 76178174174205, 590312326353680, 4578346159792815, 35745960436892046, 279290158338688617

Offset

0,2

Links

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

Example

 G.f.: A(x) = 1 + 3*x + 15*x^2 + 82*x^3 + 504*x^4 + 3198*x^5 + 21592*x^6 +...
where
A(x) = 1/((1-x)*(1-3*x^2)*(1-15*x^3)*(1-82*x^4)*(1-504*x^5)*...)^3.
Related expansion:
A(x)^(1/3) = 1 + x + 4*x^2 + 19*x^3 + 110*x^4 + 659*x^5 + 4355*x^6 +...

Prog

 (PARI) {a(n) = polcoeff(prod(k=0, n-1, 1/(1-a(k)*x^(k+1)+x*O(x^n)))^3, n)}

Crossrefs

Cf. A093637, A093638.

Sequence in context: A014276 A006964 A371616 * A192662 A213096 A052451

Adjacent sequences: A203504 A203505 A203506 * A203508 A203509 A203510

Keyword

nonn

Author

Paul D. Hanna, Jan 02 2012

Status

approved