A371679 - OEIS

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A371679

G.f. satisfies A(x) = ( 1 + x * A(x)^(3/2) * (1 + A(x)) )^2.

1, 4, 36, 424, 5696, 82720, 1264816, 20060512, 326990528, 5444291968, 92193926528, 1582961928448, 27493991536384, 482203526685696, 8527881803412224, 151909590806619648, 2723133151505640448, 49087220319316809728, 889230405958421051392

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Table of n, a(n) for n=0..18.

FORMULA

G.f.: B(x)^2 where B(x) is the g.f. of A363311.

a(n) = 2 * Sum_{k=0..n} binomial(n,k) * binomial(3*n+2*k+2,n)/(3*n+2*k+2).

PROG

(PARI) a(n, r=2, t=3, u=2) = r*sum(k=0, n, binomial(n, k)*binomial(t*n+u*k+r, n)/(t*n+u*k+r));

CROSSREFS

Cf. A363311, A371675.