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 A161759 #2 Mar 31 2012 10:26:33 %S A161759 1,2,3,4,2,5,3,6,4,14,3,5,19,4,6,21,9,5,4,40,54,6,79,5,14,7,9,69,6,5, %T A161759 146,74,19,7,89,6,9,21,29,14,164,7,6,99,104,230,9,188,209,7,335,529, %U A161759 19,139,14,329,9,7,149,21,40,750,559,174,44,7,9,349,29,14,999,1273,19,7 %N A161759 n occurs n times, as early as possible subject to the constraint that two successive occurrences of n are separated by exactly n terms. %e A161759 Index of the first occurrence of 2 is 2 and that of the second occurrence is 5, separated by a(3) and a(4), two terms. %Y A161759 A100798 %K A161759 nonn %O A161759 1,2 %A A161759 _Martins Opmanis_, Jun 18 2009