A176310 G.f.: exp( Sum_{n>=1} sigma(n*2^n)*x^n/n ).

1, 3, 12, 47, 157, 531, 1741, 5459, 16814, 51286, 152506, 447622, 1300571, 3721897, 10551143, 29663448, 82494469, 227701487, 624113377, 1697228926, 4586879327, 12323255188, 32904418872, 87395198231, 230972180615, 607363842960

Offset

0,2

Links

Table of n, a(n) for n=0..25.

Formula

The logarithmic derivative is A176311.

Prog

(PARI) {a(n)=polcoeff(exp(sum(k=1, n, sigma(k*2^k)*x^k/k)+x*O(x^n)), n)}

Crossrefs

Cf. A176311, A000203 (sigma).

Sequence in context: A344684 A216946 A303191 * A368030 A077829 A088132

Adjacent sequences: A176307 A176308 A176309 * A176311 A176312 A176313

Keyword

nonn

Author

Paul D. Hanna, Apr 15 2010

Status

approved