A181410 G.f.: exp( Sum_{n>=1} A181411(n)*x^n/n ) where A181411(n) = Sum_{k=0..n} C(n,k)*sigma(n+k).

1, 4, 17, 65, 234, 804, 2664, 8571, 26908, 82721, 249758, 742178, 2174623, 6291982, 17998815, 50957814, 142913510, 397339309, 1095887091, 3000130003, 8156568197, 22032636494, 59155443318, 157925193036, 419353166885, 1107924552070

Offset

0,2

Links

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

Example

G.f.: A(x) = 1 + 4*x + 17*x^2 + 65*x^3 + 234*x^4 + 804*x^5 +...
The logarithm of the g.f. begins:
log(A(x)) = 4*x + 18*x^2/2 + 55*x^3/3 + 150*x^4/4 + 379*x^5/5 + 915*x^6/6 + 2146*x^7/7 +...+ A181411(n)*x^n/n +...

Prog

(PARI) {a(n)=polcoeff(exp(sum(m=1, n, sum(k=0, m, binomial(m, k)*sigma(m+k))*x^m/m)+x*O(x^n)), n)}

Crossrefs

Cf. A181411.

Sequence in context: A209375 A005784 A095252 * A102207 A334827 A202555

Adjacent sequences: A181407 A181408 A181409 * A181411 A181412 A181413

Keyword

nonn

Author

Paul D. Hanna, Oct 19 2010

Status

approved