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: A017592 A046398 A033626 this_sequence A119859 A119860 A125576

Adjacent sequences: A015390 A015391 A015392 this_sequence A015394 A015395 A015396

nonn,easy

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