A378781 a(n) = n^3 * 2^n * binomial(3*n, n) / 3.
0, 2, 160, 6048, 168960, 4004000, 85542912, 1701719040, 32133218304, 583116019200, 10255365120000, 175853140869120, 2953078190899200, 48728661198077952, 792158036489666560, 12713192776728576000, 201760465448645689344, 3170643145439310643200, 49394436443159427809280
Offset: 0
Links
- Amiram Eldar, Table of n, a(n) for n = 0..500
- D. V. Chudnovsky and G. V. Chudnovsky, Classification of hypergeometric identities for Pi and other logarithms of algebraic numbers, Proceedings of the National Academy of Sciences, Vol. 95, No. 6 (1998), pp. 2744-2749. See p. 2749.
Programs
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Mathematica
a[n_] := n^3 * 2^n * Binomial[3*n, n] / 3; Array[a, 25, 0]
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PARI
a(n) = n^3 * 2^n * binomial(3*n, n) / 3;