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 A158897 #3 Mar 30 2012 18:52:03 %S A158897 6,0,11,0,0,18,0,0,0,27,0,0,0,0,38,0,0,0,0,0,51,0,0,0,0,0,0,66,0,0,0, %T A158897 0,0,0,0,83,0,0,0,0,0,0,0,0,102,0,0,0,0,0,0,0,0,0,123,0,0,0,0,0,0,0,0, %U A158897 0,0,146,0,0,0,0,0,0,0,0,0,0,0,171,0,0,0,0,0,0,0,0,0,0,0,0,198,0,0,0,0,0,0 %N A158897 The elements of A059100 at indices of triangular numbers, padded with zeros. %F A158897 a(t)=A059100(i+1) if t=A000217(i), else a(t)=0. %F A158897 a(n)=A141620(n-1)+A158405(n+1). %Y A158897 Cf. A144396. %K A158897 nonn %O A158897 1,1 %A A158897 _Paul Curtz_, Mar 29 2009 %E A158897 Edited and extended by _R. J. Mathar_, Apr 04 2009