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: A113952 A104303 A105302 this_sequence A092382 A017411 A017531

Adjacent sequences: A015418 A015419 A015420 this_sequence A015422 A015423 A015424

sign,easy

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