A206177 G.f.: exp( Sum_{n>=1} x^n/n * Sum_{k=0..n} binomial(n,k)^3 * 2^k ).

1, 3, 15, 93, 657, 5067, 41579, 357297, 3181305, 29133387, 272939679, 2605588317, 25269158105, 248367451299, 2469462766347, 24800305889217, 251258730935697, 2565372042688563, 26373806952805519, 272818956588097341, 2837840577104379201, 29667671262881320347

Offset

0,2

Comments

Logarithmic derivative yields A206178.

Links

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

Example

 G.f.: A(x) = 1 + 3*x + 15*x^2 + 93*x^3 + 657*x^4 + 5067*x^5 + 41579*x^6 +...
where
log(A(x)) = 3*x + 21*x^2/2 + 171*x^3/3 + 1521*x^4/4 + 14283*x^5/5 + 138909*x^6/6 +...+ A206178(n)*x^n/n +...

Prog

 (PARI) {a(n)=polcoeff(exp(sum(m=1, n, x^m/m*sum(k=0, m, binomial(m, k)^3*2^k))+x*O(x^n)), n)}

Crossrefs

Cf. A206178.

Sequence in context: A103210 A203014 A060066 * A366638 A272230 A308457

Adjacent sequences: A206174 A206175 A206176 * A206178 A206179 A206180

Keyword

nonn

Author

Paul D. Hanna, Feb 04 2012

Status

approved