A004129 Postage stamp problem: largest m such that there exists an n-subset S of nonnegative integers such that 1,...,m can be expressed as a sum of two distinct elements of S. (Formerly M2525)

1, 3, 6, 9, 13, 17, 22, 27, 33, 40, 47, 56, 65, 74, 83, 94, 105

Offset

2,2

References

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=2..18.

R. L. Graham and N. J. A. Sloane, On Additive Bases and Harmonious Graphs, SIAM J. Algebraic and Discrete Methods, 1 (1980), 382-404, doi:10.1137/0601045.

Simon Plouffe, Approximations de séries génératrices et quelques conjectures, Dissertation, Université du Québec à Montréal, 1992; arXiv:0911.4975 [math.NT], 2009.

Simon Plouffe, 1031 Generating Functions, Appendix to Thesis, Montreal, 1992

Index to sequences related to the postage stamp problem

Formula

The g.f. (z^4+z^3+2*z^2+2*z+1)*(z^2+z+1)/((z-1)*(z^5+z^4+z^3-z-1)) conjectured by Simon Plouffe in his 1992 dissertation is wrong. - Sean A. Irvine, Nov 21 2015

At present no g.f. is known. - N. J. A. Sloane, Jan 14 2021

Crossrefs

Sequence in context: A025205 A024190 A004116 * A219646 A366566 A185173

Adjacent sequences: A004126 A004127 A004128 * A004130 A004131 A004132

Keyword

nonn,more

Author

N. J. A. Sloane

Extensions

a(15)-a(18) from Sean A. Irvine, Nov 21 2015

Definition corrected by Rob Pratt, Jan 14 2021

Status

approved