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A218140
Central coefficients of triangle A181144.
1
1, 9, 419, 35052, 3932898, 525079969, 78585936821, 12747573200724, 2194994259274978, 395736626092691782, 73998168736285644408, 14252983638239681717320, 2813522889710891871593558, 566979470344349452319862891, 116289126161824019718614903183
OFFSET
0,2
COMMENTS
The g.f. of triangle A181144 is exp( Sum_{n>=1} [Sum_{k=0..n} C(n,k)^4*y^k] * x^n/n ).
PROG
(PARI) {a(n)=polcoeff(polcoeff(exp(sum(m=1, 2*n, sum(j=0, m, binomial(m, j)^4*y^j)*x^m/m)+O(x^(2*n+1))), 2*n, x), n, y)}
for(n=0, 20, print1(a(n), ", "))
CROSSREFS
Cf. A181144.
Sequence in context: A179433 A091061 A024123 * A292073 A232249 A229843
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Oct 21 2012
STATUS
approved