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A368441
Expansion of e.g.f. exp(x) / (4 - 3*exp(3*x)).
2
1, 10, 208, 6508, 271468, 14154580, 885638908, 64649204308, 5393387534428, 506188870889140, 52786278954586108, 6055112126576175508, 757725480419984012188, 102722055234542078115700, 14996854976334688765608508, 2345848207305916218955201108
OFFSET
0,2
FORMULA
a(n) = 1 + 3 * Sum_{k=1..n} 3^k * binomial(n,k) * a(n-k).
PROG
(PARI) a_vector(n) = my(v=vector(n+1)); for(i=0, n, v[i+1]=1+3*sum(j=1, i, 3^j*binomial(i, j)*v[i-j+1])); v;
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Dec 24 2023
STATUS
approved