A183035 G.f.: A(x) = x*(1-x^2)*Product_{n>=1} (1 + x^(4^n))^3.

1, 0, -1, 0, 3, 0, -3, 0, 3, 0, -3, 0, 1, 0, -1, 0, 3, 0, -3, 0, 9, 0, -9, 0, 9, 0, -9, 0, 3, 0, -3, 0, 3, 0, -3, 0, 9, 0, -9, 0, 9, 0, -9, 0, 3, 0, -3, 0, 1, 0, -1, 0, 3, 0, -3, 0, 3, 0, -3, 0, 1, 0, -1, 0, 3, 0, -3, 0, 9, 0, -9, 0, 9, 0, -9, 0, 3, 0, -3, 0, 9, 0, -9, 0, 27, 0, -27, 0, 27, 0, -27, 0, 9, 0

Offset: 1

Author

Paul D. Hanna, Dec 19 2010

Keywords

• sign

Examples

			G.f.: A(x) = x - x^3 + 3*x^5 - 3*x^7 + 3*x^9 - 3*x^11 + x^13 - x^15 +...
		

Crossrefs

Cf. A183034.

Programs

PARI

{a(n)=local(L4n=ceil(log(n+1)/log(4)));polcoeff(x*(1-x^2)*prod(k=1,L4n,1 + x^(4^k)+x*O(x^n))^3,n)}

Formula

a(2n) = 0.