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A118367 Largest number that is not the sum of five n-gonal numbers. 1
0, 0, 0, 26, 47, 188, 245, 343, 494, 821, 901, 1283, 1729, 1972, 2715, 3795, 4030, 4788, 5681, 6379, 6948, 9484, 9913, 10342, 10771, 14064, 15035, 19182, 19865, 20548, 27315, 28194, 29073, 29952, 33351, 34302, 35253, 50772, 52106, 53440, 54774 (list; graph; refs; listen; history; text; internal format)
OFFSET
3,4
COMMENTS
Legendre proved that a number N is the sum of five n-gonal numbers if N >= 28(n-2)^3. For odd n, four n-gonal numbers are enough. See A118368.
REFERENCES
Melvyn B. Nathanson, Additive number theory: the classical bases, Springer, 1996.
LINKS
R. K. Guy, Every number is expressible as the sum of how many polygonal numbers?, Amer. Math. Monthly 101 (1994), 169-172.
Eric Weisstein's World of Mathematics, Polygonal Number
CROSSREFS
Cf. A118368.
Sequence in context: A039458 A291672 A159651 * A316120 A261932 A364025
KEYWORD
nonn
AUTHOR
T. D. Noe, Apr 25 2006
STATUS
approved

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Last modified July 19 05:20 EDT 2024. Contains 374388 sequences. (Running on oeis4.)