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A001214 a(n) is the solution to the postage stamp problem with n denominations and 4 stamps.

%I A001214 M3391 N1559 #44 Jan 13 2023 21:12:48
%S A001214 4,10,26,44,70,108,162,228,310,422,550,700,878,1079,1344,1606,1944,
%T A001214 2337,2766,3195,3668,4251,4923,5631,6429
%N A001214 a(n) is the solution to the postage stamp problem with n denominations and 4 stamps.
%C A001214 _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.
%D A001214 R. K. Guy, Unsolved Problems in Number Theory, C12.
%D A001214 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A001214 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A001214 R. Alter and J. A. Barnett, <a href="http://www.jstor.org/stable/2321610">A postage stamp problem</a>, Amer. Math. Monthly, 87 (1980), 206-210.
%H A001214 M. F. Challis, <a href="http://dx.doi.org/10.1093/comjnl/36.2.117">Two new techniques for computing extremal h-bases A_k</a>, Comp. J. 36(2) (1993) 117-126
%H A001214 M. F. Challis and J. P. Robinson, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL13/Challis/challis6.html">Some Extremal Postage Stamp Bases</a>, J. Integer Seq., 13 (2010), Article 10.2.3. [From John P Robinson (john-robinson(AT)uiowa.edu), Feb 18 2010]
%H A001214 Erich Friedman, <a href="https://erich-friedman.github.io/mathmagic/0403.html">Postage stamp problem</a>
%H A001214 R. L. Graham and N. J. A. Sloane, <a href="http://dx.doi.org/10.1137/0601045">On Additive Bases and Harmonious Graphs</a>, SIAM J. Algebraic and Discrete Methods, 1 (1980), 382-404.
%H A001214 R. L. Graham and N. J. A. Sloane, <a href="http://neilsloane.com/doc/RLG/073.pdf">On Additive Bases and Harmonious Graphs</a>
%H A001214 W. F. Lunnon, <a href="https://doi.org/10.1093/comjnl/12.4.377">A postage stamp problem</a>, Comput. J. 12 (1969) 377-380.
%Y A001214 Postage stamp sequences: A001208, A001209, A001210, A001211, A001212, A001213, A001214, A001215, A001216, A005342, A005343, A005344, A014616, A053346, A053348, A075060, A084192, A084193.
%Y A001214 A row or column of the array A196416 (possibly with 1 subtracted from it).
%K A001214 nonn,more
%O A001214 1,1
%A A001214 _N. J. A. Sloane_
%E A001214 a(10) from Challis added by _R. J. Mathar_, Apr 01 2006
%E A001214 Entry improved by comments from John Seldon (johnseldon(AT)onetel.com), Sep 15 2004
%E A001214 a(11) from Challis & Robinson added by John P Robinson (john-robinson(AT)uiowa.edu), Feb 18 2010
%E A001214 a(12)-a(25) from Friedman added by _Robert Price_, Jul 19 2013