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: A092381 A084482 A034654 this_sequence A015431 A017410 A017530

Adjacent sequences: A015398 A015399 A015400 this_sequence A015402 A015403 A015404

nonn,easy

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