9,2

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.

(Other) sage: [gaussian_binomial(n, 9, -9) for n in xrange(9, 15)] # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 25 2009]

Sequence in context: A022239 A113739 A159448 this_sequence A032757 A167517 A159300

Adjacent sequences: A015378 A015379 A015380 this_sequence A015382 A015383 A015384

sign,easy

Olivier Gerard (olivier.gerard(AT)gmail.com)