A364626 - OEIS

A364626

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

1, 3, 7, 19, 63, 231, 895, 3615, 15055, 64111, 277791, 1220767, 5427775, 24371199, 110350335, 503289727, 2309992959, 10661634303, 49452179455, 230391918591, 1077644520703, 5058766156543, 23824929459711, 112541456498175, 533063457631231, 2531252417738751

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..25.

FORMULA

a(n) = Sum_{k=0..floor(n/2)} binomial(n+4*k+2,6*k+2) * binomial(3*k,k) / (2*k+1).

PROG

(PARI) a(n) = sum(k=0, n\2, binomial(n+4*k+2, 6*k+2)*binomial(3*k, k)/(2*k+1));

CROSSREFS

Cf. A364625, A364627.

Cf. A086631.