A368453 Expansion of e.g.f. 3*exp(x) / (4 - exp(3*x)).

1, 2, 8, 52, 452, 4892, 63508, 962012, 16654772, 324375292, 7019618708, 167098274972, 4339293330292, 122075401356092, 3698469101172308, 120054668185331932, 4156854586083305012, 152925374174876071292, 5956866331612558316308, 244927333201908131524892

Offset

0,2

Links

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

Formula

a(n) = 1 + Sum_{k=1..n} 3^(k-1) * binomial(n,k) * a(n-k).

Prog

(PARI) a_vector(n) = my(v=vector(n+1)); for(i=0, n, v[i+1]=1+sum(j=1, i, 3^(j-1)*binomial(i, j)*v[i-j+1])); v;

Crossrefs

Cf. A151919, A368440, A368441.

Cf. A368450.

Sequence in context: A136794 A125787 A358031 * A007832 A111088 A367371

Adjacent sequences: A368450 A368451 A368452 * A368454 A368455 A368456

Keyword

nonn

Author

Seiichi Manyama, Dec 24 2023

Status

approved