

A118278


Conjectured largest number that is not the sum of three ngonal numbers, or 1 if there is no largest number.


16



0, 1, 33066, 146858, 273118, 1, 1274522, 2117145, 3613278, 1, 7250758, 1, 12911636, 1, 22655394, 26801303, 25049533, 1, 56922533, 115715602, 81539010, 1, 85105105, 1, 106555658, 1, 233296317, 267370631, 286763923, 1, 358322750
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

3,3


COMMENTS

Extensive calculations show that if a(n) >= 0, then every number greater than a(n) can be represented as the sum of three ngonal numbers. a(3)=0 because every number can be written as the sum of three triangular numbers. When n is a multiple of 4, there is an infinite set of numbers not representable. For n=14, there appears to be a sparse, but infinite, set of numbers not representable.


LINKS



CROSSREFS

Cf. A118279 (number of numbers not representable).
Cf. A003679 (not the sum of three pentagonal numbers).
Cf. A007536 (not the sum of three hexagonal numbers).
Cf. A213523 (not the sum of three heptagonal numbers).
Cf. A213524 (not the sum of three octagonal numbers).
Cf. A213525 (not the sum of three 9gonal numbers).
Cf. A214419 (not the sum of three 10gonal numbers).
Cf. A214420 (not the sum of three 11gonal numbers).
Cf. A214421 (not the sum of three 12gonal numbers).


KEYWORD

sign


AUTHOR



EXTENSIONS



STATUS

approved



