This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A249408 #6 Nov 01 2014 18:53:19 %S A249408 1,399,8099,33123,93635,159200,256035,492803,864899,1416099,2196323, %T A249408 3261635,4674243,6502499,8820899,12531599,16257023,20757135,26132543, %U A249408 32489999,39942399,48608783,58614335,65593800,73205135,86713343,102009999,119246399,138579983 %N A249408 Numbers in A249406 that are not of the form m*(m+1). %H A249408 Reinhard Zumkeller, <a href="/A249408/b249408.txt">Table of n, a(n) for n = 1..150</a> %F A249408 A005369(a(n)) = 0. %o A249408 (Haskell) %o A249408 import Data.List ((\\)) %o A249408 a249408 n = a249408_list !! (n-1) %o A249408 a249408_list = filter ((== 0) . a005369) a249406_list %Y A249408 Cf. A249406, A005369, A002378, subsequence of A078358. %K A249408 nonn %O A249408 1,2 %A A249408 _Reinhard Zumkeller_, Oct 31 2014