9,2

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.

Adjacent sequences: A015368 A015369 A015370 this_sequence A015372 A015373 A015374

Sequence in context: A069309 A086806 A006107 this_sequence A045106 A137201 A121205

sign,easy

Olivier Gerard (olivier.gerard(AT)gmail.com)