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 A271020 #7 Apr 05 2016 00:20:00 %S A271020 49288842,62620221,116153046,128221941,132479727,443599581,563581992, %T A271020 750128651,1045377417,1153997472,1192317546,1232221059,1565505534, %U A271020 1881096741,2192812511,2415153276,2903826159,3068390847,3205548534,3311993184,3647394275,3992396232 %N A271020 Magic sums of 3 X 3 semimagic squares of triangular numbers whose rows, columns, and at least one of the two main diagonals sum to the same number. %H A271020 Arkadiusz Wesolowski, <a href="/A271020/a271020.txt">Examples of these semimagic squares</a> %H A271020 <a href="/index/Mag#magic">Index entries for sequences related to magic squares</a> %Y A271020 Cf. A271021, A271022. Subsequence of A269060. %K A271020 nonn %O A271020 1,1 %A A271020 _Arkadiusz Wesolowski_, Mar 28 2016