OFFSET
6,2
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 = 6..100
FORMULA
G.f.: x^6/((1-x)*(1+11*x)*(1-121*x)*(1+1331*x)*(1-14641*x)*(1+161051*x)*(1-1771561*x)). - Vincenzo Librandi, Oct 30 2012
a(n) = (-1 +11^(6n-15) +198134223*11^(2n-9)*(1 -11^(2n-5)) +1330*11^(n-5)*(111 +111*11^(4n-10) -1637362*11^(2n-7))*(-1)^n) / 8011794142389510144000. - Bruno Berselli, Oct 30 2012
MATHEMATICA
Table[QBinomial[n, 6, -11], {n, 6, 10}] (* Vincenzo Librandi, Oct 29 2012 *)
PROG
(Sage) [gaussian_binomial(n, 6, -11) for n in range(6, 13)] # Zerinvary Lajos, May 27 2009
(Magma) /* By definition: */ r:=6; q:=-11; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..12]]; // Bruno Berselli, Oct 30 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Olivier Gérard, Dec 11 1999
STATUS
approved