A180917 - OEIS

%I #9 Feb 16 2020 20:08:17

%S 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,

%T 33,34,35,38,39,40,41,44,45,46,47,49,50,51,52,55,56,58,60,61,62,64,65,

%U 66,67,68,71,72,73,76,77,78,79,81,82,84,85,87,88,92,93,94,97,98,99,101

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

%C Complement of A117105. This is to heptagonal numbers A000566,

%C as A007536 is to hexagonal numbers A000384,

%C as A003679 is to pentagonal numbers A000326,

%C and as A004214 is to squares A000290.

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

%C Last element appears to be a(1671) = 273118. - _Charles R Greathouse IV_, Sep 27 2010

%H Charles R Greathouse IV, <a href="/A180917/b180917.txt">Table of n, a(n) for n = 1..1671</a>

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

%K easy,nonn

%O 1,2

%A _Jonathan Vos Post_, Sep 23 2010