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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

Table of n, a(n) for n=3..43.

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 A324041

Adjacent sequences:  A118364 A118365 A118366 * A118368 A118369 A118370

KEYWORD

nonn

AUTHOR

T. D. Noe, Apr 25 2006

STATUS

approved

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Last modified September 27 22:01 EDT 2022. Contains 357063 sequences. (Running on oeis4.)