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 A274633 #3 Jul 08 2016 11:18:14 %S A274633 1,5,9,6,4,14,2,19,11,3,20,15,8,10,25,22,33,27,7,28,43,29,36,17,12,13, %T A274633 16,62,18,40,66,35,71,59,77,74,50,45,49,85,60,21,24,58,23,99,30,78,32, %U A274633 31,67,103,110,37,42,34,26,38,73,83,80,39,134,47,79,105,41,95,148,106,150,102,44,92 %N A274633 Main diagonal of array in A274630. %Y A274633 Cf. A274630, A269526. %K A274633 nonn %O A274633 1,2 %A A274633 _N. J. A. Sloane_, Jul 08 2016