A015212 Sum of Gaussian binomial coefficients for q=21.

1, 2, 24, 928, 224096, 180925632, 915592324864, 15519120649837568, 1649093881865807133696, 586980815917441872922703872, 1309843539264798142345101012967424, 9790772765676733007363874643686313525248

Offset: 0

Author

N. J. A. Sloane, Olivier Gérard

Keywords

• nonn

References

• J. Goldman and G.-C. Rota, The number of subspaces of a vector space, pp. 75-83 of W. T. Tutte, editor, Recent Progress in Combinatorics. Academic Press, NY, 1969.
• I. P. Goulden and D. M. Jackson, Combinatorial Enumeration. Wiley, NY, 1983, p. 99.
• M. Sved, Gaussians and binomials, Ars. Combinatoria, 17A (1984), 325-351.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..50
• Kent E. Morrison, Integer Sequences and Matrices Over Finite Fields, Journal of Integer Sequences, Vol. 9 (2006), Article 06.2.1.

Crossrefs

Row sums of triangle A022185.

Programs

Mathematica

Total/@Table[QBinomial[n, m, 21], {n, 0, 20}, {m, 0, n}] (* Vincenzo Librandi, Nov 02 2012 *)

Formula

a(0) = 1, a(1) = 2, a(n) = 2*a(n-1) + a(n-2)*((21^(n-1)) - 1). - Vincenzo Librandi, Nov 02 2012