OFFSET
0,2
REFERENCES
J. C. P. Miller, On the enumeration of partially ordered sets of integers, pp. 109-124 of T. P. McDonough and V. C. Mavron, editors, Combinatorics: Proceedings of the Fourth British Combinatorial Conference 1973. London Mathematical Society, Lecture Note Series, Number 13, Cambridge University Press, NY, 1974. The g.f. is G(t) at the foot of page 123.
LINKS
Ray Chandler, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (2, -1, 1, -1, 0, 0, -1, 1, -1, 1, -2, 3, -2, 3, -1, 1, -1, 0, -1, 0, -1, -2, 2, -2, 3, -2, 4, -2, 3, -2, 2, -2, -1, 0, -1, 0, -1, 1, -1, 3, -2, 3, -2, 1, -1, 1, -1, 0, 0, -1, 1, -1, 2, -1).
MAPLE
(1+5*x+5*x^2+x^3)/mul(1-x^i, i=1..10);
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 23 2015
STATUS
approved