A193103 G.f.: exp( Sum_{n>=1} 2*sigma(n*4^n)*x^n/n ).

1, 14, 161, 1678, 15524, 134844, 1113797, 8791370, 66966377, 495285252, 3566916109, 25105766336, 173194384597, 1173147905334, 7817490983485, 51328840496684, 332461481754542, 2126710086580138, 13448964442250078, 84145658562788118

Offset

0,2

Links

Table of n, a(n) for n=0..19.

Example

 G.f.: A(x) = 1 + 14*x + 161*x^2 + 1678*x^3 + 15524*x^4 + 134844*x^5 +...
log(A(x)) = 14*x + 126*x^2/2 + 1016*x^3/3 + 4094*x^4/4 + 24564*x^5/5 + 131064*x^6/6 + 524272*x^7/7 +...+ 2*sigma(n*4^n)*x^n/n +...

Prog

 (PARI) {a(n)=polcoeff(exp(sum(m=1, n, 2*sigma(m*4^m)*x^m/m)+x*O(x^n)), n)}

Crossrefs

Cf. A176310, A193102, A193104.

Sequence in context: A343093 A229611 A282043 * A016206 A161158 A238116

Adjacent sequences: A193100 A193101 A193102 * A193104 A193105 A193106

Keyword

nonn

Author

Paul D. Hanna, Jul 15 2011

Status

approved