A256976 G.f.: (1 + x^4 - x^5 - x^6 - x^10 - x^11 + x^12 + x^16)/Product_{i=1..8} (1 - x^i).

1, 1, 2, 3, 6, 7, 11, 15, 22, 28, 38, 47, 64, 77, 99, 120, 152, 179, 221, 260, 316, 367, 439, 506, 600, 685, 800, 910, 1056, 1190, 1368, 1536, 1753, 1957, 2217, 2464, 2778, 3073, 3441, 3795, 4232, 4645, 5155, 5643, 6237, 6804, 7489

Offset: 0

Author

N. J. A. Sloane, Apr 22 2015

Keywords

• nonn

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_{ref}(t) on page 122, corrected. (The version of G_{ref}(t) stated on page 122 gives A256975, which does not match the terms on page 123.)

Links

• Ray Chandler, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (-1, 0, 1, 2, 2, 2, 1, 0, -2, -4, -5, -4, -2, 0, 3, 5, 6, 5, 3, 0, -2, -4, -5, -4, -2, 0, 1, 2, 2, 2, 1, 0, -1, -1).

Crossrefs

Cf. A256975.

Programs

Maple

(1+x^4-x^5-x^6-x^10-x^11+x^12+x^16)/mul(1-x^i, i=1..8);