11,2

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: A022219 A104965 A034610 this_sequence A105005 A112429 A104923

Adjacent sequences: A015407 A015408 A015409 this_sequence A015411 A015412 A015413

sign,easy

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