A366177 - OEIS

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A366177

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

1

1, 2, 9, 55, 382, 2866, 22648, 185722, 1565725, 13486036, 118163960, 1049908872, 9437623630, 85671158757, 784247925911, 7231502249005, 67106161264660, 626221543735984, 5872908642398977, 55323451127462123, 523240983692525619, 4966658879361416551

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..21.

FORMULA

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

PROG

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

CROSSREFS

Partial sums give A364620.

Cf. A199475, A346626, A366178.

Sequence in context: A001757 A267225 A078455 * A355281 A036074 A231172

Adjacent sequences: A366174 A366175 A366176 * A366178 A366179 A366180

KEYWORD

nonn

AUTHOR

Seiichi Manyama, Oct 03 2023

STATUS

approved