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 A242401 #21 Jun 09 2022 21:51:27
%S A242401 2,5,7,8,11,12,13,14,17,18,19,20,22,23,24,26,27,29,30,31,32,33,34,35,
%T A242401 37,38,39,40,41,42,43,44,46,47,48,50,51,52,53,54,56,57,58,59,60,61,62,
%U A242401 63,65,67,68,69,70,71,72,73,74,75,76,77,79,80,82,83,84
%N A242401 Numbers that are neither triangular nor square.
%H A242401 Reinhard Zumkeller, <a href="/A242401/b242401.txt">Table of n, a(n) for n = 1..10000</a>
%F A242401 A010052(a(n)) + A010054(a(n)) = 0. - _Reinhard Zumkeller_, May 13 2014
%e A242401 6 is not a term because it's triangular;
%e A242401 9 is not a term because it's square.
%t A242401 With[{nn=90},Complement[Range[nn],Range[Floor[Sqrt[nn]]]^2,Accumulate[ Range[ Floor[(Sqrt[1+8nn]-1)/2]]]]] (* _Harvey P. Dale_, May 03 2022 *)
%o A242401 (Sage)
%o A242401 [x for x in [1..100] if not(is_square(x)) and not(is_triangular_number(x))] # _Tom Edgar_, May 13 2014
%o A242401 (Haskell)
%o A242401 a242401 n = a242401_list !! (n-1)
%o A242401 a242401_list = filter ((== 0) . a010054) a000037_list
%o A242401 -- _Reinhard Zumkeller_, May 13 2014
%Y A242401 Cf. A000217, A000290.
%Y A242401 Cf. A005214 (complement); intersection of A000037 and A014132.
%K A242401 nonn,easy
%O A242401 1,1
%A A242401 _J. Lowell_, May 13 2014