10,2

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.

Sequence in context: A023347 A063875 A113150 this_sequence A043623 A141296 A103913

Adjacent sequences: A015387 A015388 A015389 this_sequence A015391 A015392 A015393

nonn,easy

Olivier Gerard (ogerard(AT)ext.jussieu.fr)