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: A015382 A115385 A122532 this_sequence A114261 A136953 A136961

Adjacent sequences: A015391 A015392 A015393 this_sequence A015395 A015396 A015397

nonn,easy

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