A256975 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, 9, 15, 21, 32, 44, 64, 87, 122, 161, 217, 282, 372, 475, 613, 772, 978, 1215, 1515, 1860, 2290, 2781, 3382, 4068, 4896, 5836, 6958, 8228, 9727, 11417, 13393, 15614, 18190, 21073, 24391, 28095, 32330, 37039, 42391, 48325

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) as stated on page 122, although in fact this is wrong and does not match the terms shown on page 123 - there are four missing minus signs in the g.f. The correct G_{ref}(t) is in A256976.

Crossrefs

Cf. A256976.

Programs

Maple

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