A168590 G.f.: exp( Sum_{n>=1} A168591(n)*x^n/n ), where A168591(n) = sum of the n-th power of the trinomial coefficients in row n of triangle A027907.

1, 3, 14, 310, 71399, 153056789, 2826352872319, 445742192193898313, 602479884829000885595175, 7000510736697461064666950774905, 701725717683874683612335083605682943282

Offset

0,2

Links

Table of n, a(n) for n=0..10.

Example

G.f.: A(x) = 1 + 3*x + 14*x^2 + 310*x^3 + 71399*x^4 +...
log(A(x)) = 3*x + 19*x^2/2 + 831*x^3/3 + 281907*x^4/4 +...+ A168591(n)*x^n/n +...

Prog

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

Crossrefs

Cf. A168591, A168592, A168593, A027907.

Sequence in context: A001320 A133028 A144985 * A309028 A297487 A297484

Adjacent sequences: A168587 A168588 A168589 * A168591 A168592 A168593

Keyword

nonn

Author

Paul D. Hanna, Dec 01 2009

Status

approved