A355070 G.f.: Sum_{n>=0} a(n)*x^n/(n!*3^(n*(n-1)/2)) = log( Sum_{n>=0} x^n/(n!*3^(n*(n-1)/2)) ).

0, 1, -2, 28, -1808, 469072, -456745472, 1601325615808, -19650153075181568, 826737899840505194752, -117393483573257494026125312, 55564698792825562646890851908608, -86789641569440259960965030826164092928

Offset

0,3

Links

Table of n, a(n) for n=0..12.

Formula

a(0) = 0; a(n) = 1 - Sum_{k=1..n-1} 3^(k*(n-k)) * binomial(n-1,k) * a(n-k).

Prog

(PARI) a(n) = n!*3^(n*(n-1)/2)*polcoef(log(sum(k=0, n, x^k/(k!*3^(k*(k-1)/2)))+x*O(x^n)), n);
(PARI) a_vector(n) = my(v=vector(n+1)); v[1]=0; for(i=1, n, v[i+1]=1-sum(j=1, i-1, 3^(j*(i-j))*binomial(i-1, j)*v[i-j+1])); v;

Crossrefs

Cf. A134531, A355071.

Cf. A188457, A355073.

Sequence in context: A238817 A202942 A356518 * A326366 A177400 A230700

Adjacent sequences: A355067 A355068 A355069 * A355071 A355072 A355073

Keyword

sign

Author

Seiichi Manyama, Jun 18 2022

Status

approved