

A001214


a(n) = solution to the postage stamp problem with n denominations and 4 stamps.
(Formerly M3391 N1559)


21



4, 10, 26, 44, 70, 108, 162, 228, 310, 422, 550, 700, 878, 1079, 1344, 1606, 1944, 2337, 2766, 3195, 3668, 4251, 4923, 5631, 6429
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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. Alter and J. A. Barnett, A postage stamp problem, Amer. Math. Monthly, 87 (1980), 206210.
R. L. Graham and N. J. A. Sloane, On Additive Bases and Harmonious Graphs, SIAM J. Algebraic and Discrete Methods, 1 (1980), 382404.
R. K. Guy, Unsolved Problems in Number Theory, C12.
W. F. Lunnon, A postage stamp problem. Comput. J. 12 (1969) 377380.
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.
Erich Friedman, Postage stamp problem
R. L. Graham and N. J. A. Sloane, On Additive Bases and Harmonious Graphs
M. F. Challis, Two new techniques for computing extremal hbases A_k, Comp. J. 36(2) (1993) 117126
M. F. Challis and J. P. Robinson, Some Extremal Postage Stamp Bases, J. Integer Seq., 13 (2010), Article 10.2.3. [From John P Robinson (johnrobinson(AT)uiowa.edu), Feb 18 2010]


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: A145775 A283958 A255718 * A200455 A269064 A022812
Adjacent sequences: A001211 A001212 A001213 * A001215 A001216 A001217


KEYWORD

nonn


AUTHOR

N. J. A. Sloane.


EXTENSIONS

Added a(10) from Challis.  R. J. Mathar, Apr 01 2006
Entry improved by comments from John Seldon (johnseldon(AT)onetel.com), Sep 15 2004
Added a(11) from Challis & Robinson. John P Robinson (johnrobinson(AT)uiowa.edu), Feb 18 2010
a(12)a(25) from Friedman by Robert Price, Jul 19 2013


STATUS

approved



