S000816


Numbers that are not the sum of 3 generalized 17-gonal numbers.

4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 20, 21, 22, 23, 24, 25, 26, 27, 30, 33, 36, 37, 38, 39, 40, 41, 46, 47, 52, 53, 54, 55, 56, 59, 64, 67, 68, 69, 70, 72, 73, 75, 78, 80, 81, 83, 84, 85, 90, 93, 98, 99, 106, 107, 114, 116, 117, 119, 120, 123, 124, 126, 127, 132

1

S000816

It appears that 75150 is the last number not representable as the sum of 3 generalized 17-gonal numbers.

T. D. Noe, Plot of 641 terms

T. D. Noe, Table of 641 terms

Eric W. Weisstein, MathWorld: Polygonal Number

(Mma) f = 17; nn = 200; t = Table[k ((f - 2) k - (f - 4))/2, {k, -nn, nn}]; t2 = Select[Union[Flatten[Table[a + b + c, {a, t}, {b, t}, {c, t}]]], # <= t[[-1]] &]; Complement[Range[t[[-1]]], t2]

Cf. A118282S000806-S000819.

nonn,fini

T. D. Noe, Dec 28 2015

© Tony D Noe 2014-2015