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 A357505 #16 Jun 04 2023 08:56:08
%S A357505 0,2,5,8,12,14,17,19,20,23,26,30,32,33,35,40,41,44,47,50,52,53,54,59,
%T A357505 62,63,68,71,74,75,77,80,82,85,86,89,90,95,96,98,103,104,107,109,110,
%U A357505 113,116,117,118,122,124,125,128,129,131,132,134,138,140,143,145,147
%N A357505 Numbers that are not sum of two distinct triangular numbers.
%C A357505 This sequence differs from A020757 in including the terms that are twice a triangular number and that cannot be expressed as a sum of two distinct triangular numbers: 0, 2, 12, 20, 30, 90, 110, 132, ... = 2*A357529.
%t A357505 TriangularQ[n_]:=IntegerQ[(Sqrt[1+8n]-1)/2]; A000217[n_]:=n(n+1)/2; a={}; For[k=0, k<=148, k++, ok=1; For[h=0, A000217[h]<k/2, h++, If[TriangularQ[k - A000217[h]] , ok=0]]; If[ok==1, AppendTo[a, k]]]; a (* _Stefano Spezia_, Nov 06 2022 *)
%Y A357505 Cf. A000217, A020757 (subsequence), A357504 (complement).
%Y A357505 Cf. A357529.
%K A357505 nonn,easy
%O A357505 1,2
%A A357505 _Stefano Spezia_, Oct 01 2022