A180917 Numbers that are not the sum of three positive heptagonal numbers.

1, 2, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 16, 17, 18, 19, 22, 23, 24, 25, 27, 28, 29, 30, 31, 33, 34, 35, 38, 39, 40, 41, 44, 45, 46, 47, 49, 50, 51, 52, 55, 56, 58, 60, 61, 62, 64, 65, 66, 67, 68, 71, 72, 73, 76, 77, 78, 79, 81, 82, 84, 85, 87, 88, 92, 93, 94, 97, 98, 99, 101

Offset

1,2

Comments

Complement of A117105. This is to heptagonal numbers A000566,

as A007536 is to hexagonal numbers A000384,

as A003679 is to pentagonal numbers A000326,

and as A004214 is to squares A000290.

This sequence is presumably finite: what is its likely last element?

Last element appears to be a(1671) = 273118. - Charles R Greathouse IV, Sep 27 2010

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..1671

Crossrefs

Cf. A000290, A000326, A000384, A000566, A003679, A004214, A007536, A117105.

Sequence in context: A047263 A039244 A160044 * A127428 A039187 A001963

Adjacent sequences: A180914 A180915 A180916 * A180918 A180919 A180920

Keyword

easy,nonn

Author

Jonathan Vos Post, Sep 23 2010

Status

approved