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A001214
a(n) is the solution to the postage stamp problem with n denominations and 4 stamps.
(Formerly M3391 N1559)
20
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
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
R. Alter and J. A. Barnett, A postage stamp problem, Amer. Math. Monthly, 87 (1980), 206-210.
M. F. Challis, Two new techniques for computing extremal h-bases A_k, Comp. J. 36(2) (1993) 117-126
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 (john-robinson(AT)uiowa.edu), Feb 18 2010]
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.
CROSSREFS
A row or column of the array A196416 (possibly with 1 subtracted from it).
Sequence in context: A283958 A335637 A255718 * A200455 A269064 A307415
KEYWORD
nonn,more
EXTENSIONS
a(10) from Challis added by R. J. Mathar, Apr 01 2006
Entry improved by comments from John Seldon (johnseldon(AT)onetel.com), Sep 15 2004
a(11) from Challis & Robinson added by John P Robinson (john-robinson(AT)uiowa.edu), Feb 18 2010
a(12)-a(25) from Friedman added by Robert Price, Jul 19 2013
STATUS
approved