A144485 a(n) = (3n + 2)*binomial(3n + 1,n).

2, 20, 168, 1320, 10010, 74256, 542640, 3922512, 28120950, 200300100, 1419269280, 10013421600, 70394353848, 493362138080, 3448674255840, 24051721745568, 167405449649550, 1163116182943260, 8068463611408200, 55891260077406600

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

O. Egecioglu, T. Redmond, C. Ryavec, Almost product evaluation of Hankel Determinants, arXiv:0704.3398.

Formula

a(n) = (3n+2)*A045721(n). - R. J. Mathar, Feb 01 2014

a(n) = 2*A090763(n). - Alois P. Heinz, Feb 01 2014

Maple

a:= proc(n) option remember; `if`(n=0, 2,
      3*(3*n+1)*(3*n+2)*a(n-1)/(2*n*(2*n+1)))
    end:
seq(a(n), n=0..30);  # Alois P. Heinz, Feb 01 2014

Mathematica

a[k_] = (3k + 2)Binomial[3k + 1, k]; Table[a[k], {k, 0, 30}]

Prog

(Magma) [(3*n+2)*Binomial(3*n+1, n): n in [0..20]]; // Vincenzo Librandi, Feb 14 2014

Crossrefs

Sequence in context: A093130 A043029 A164944 * A115489 A367939 A105493

Adjacent sequences: A144482 A144483 A144484 * A144486 A144487 A144488

Keyword

nonn,easy

Author

Roger L. Bagula, Oct 12 2008

Status

approved