8,2

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: A104826 A092014 A114667 this_sequence A134359 A013913 A069337

Adjacent sequences: A015357 A015358 A015359 this_sequence A015361 A015362 A015363

nonn,easy

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