A001213 a(n) is the solution to the postage stamp problem with n denominations and 3 stamps. (Formerly M2647 N1340)

3, 7, 15, 24, 36, 52, 70, 93, 121, 154, 186, 225, 271, 323, 385, 450, 515, 606, 684, 788, 865, 977, 1091, 1201, 1361

Offset

1,1

Comments

Fred Lunnon [W. F. Lunnon] defines "solution" to be the smallest value not obtainable by the best set of stamps. The solutions given are one lower than this, that is, the sequence gives the largest number obtainable without a break using the best set of stamps.

References

R. K. Guy, Unsolved Problems in Number Theory, C12.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

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=1..25.

R. Alter and J. A. Barnett, A postage stamp problem, Amer. Math. Monthly, 87 (1980), 206-210.

Erich Friedman, Postage stamp problem

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

R. L. Graham and N. J. A. Sloane, On Additive Bases and Harmonious Graphs

W. F. Lunnon, A postage stamp problem, Comput. J. 12 (1969) 377-380.

Eric Weisstein's World of Mathematics, Postage stamp problem

Crossrefs

Postage stamp sequences: A001208, A001209, A001210, A001211, A001212, A001213, A001214, A001215, A001216, A005342, A005343, A005344, A014616, A053346, A053348, A075060, A084192, A084193.

A row or column of the array A196416 (possibly with 1 subtracted from it).

Sequence in context: A283865 A283607 A375704 * A066044 A066460 A114221

Adjacent sequences: A001210 A001211 A001212 * A001214 A001215 A001216

Keyword

nonn,more

Author

N. J. A. Sloane

Extensions

Entry improved by comments from John Seldon (johnseldon(AT)onetel.com), Sep 15 2004

More terms from Al Zimmermann, Feb 20 2002

Further terms from Friedman web site, Jun 20 2003

Incorrect value of a(17) removed by Al Zimmermann, Nov 08 2009

a(17)-a(25) from Friedman added by Robert Price, Jul 19 2013

Status

approved