A175991 a(n) = binomial(binomial(binomial(n, 2), 3), 4)/5.

969, 1642914, 352470391, 25957590316, 958073067315, 21639468423573, 337726148030733, 3946787095970862, 36534727415378192, 279109860906071195, 1815047255456722287, 10290566991057546557, 51837653320551263438, 235568544405588437778, 977816056476957297015, 3745739023587032569461, 13356862465688668653111

Offset: 4

Author

Roger L. Bagula, Dec 06 2010

Keywords

• nonn

Crossrefs

Cf. A093566.

Programs

Mathematica

Table[Binomial[Binomial[Binomial[n, 2], 3], 4]/5, {n, 4, 30}]

Formula

From R. J. Mathar, Dec 08 2010: (Start)

a(n) = binomial(A093566(n+1),4)/5.

a(n) = n *(n-1) *(n-2) *(n-3) *(n+2) *(n+1) *(n^2-n-4) *(n^6-3*n^5-3*n^4+11*n^3+2*n^2-8*n-96) *(n^4-2*n^3+n^2+8) *(n^6-3*n^5-3*n^4+11*n^3+2*n^2-8*n-144) /637009920. (End)