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: A036471 A083635 A116306 this_sequence A036472 A114682 A123201

Adjacent sequences: A015405 A015406 A015407 this_sequence A015409 A015410 A015411

sign,easy

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