0,2

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.

T. D. Noe, Table of n, a(n) for n=0..25

Sequence in context: A001425 A050284 A096759 this_sequence A003371 A113253 A064227

Adjacent sequences: A006100 A006101 A006102 this_sequence A006104 A006105 A006106

nonn,easy

njas