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 A142883 #6 Oct 04 2015 01:49:26 %S A142883 0,7,5,39,4,95,33,175,14,279,85,407,30,559,161,735,52,935,261,1159,80, %T A142883 1407,385,1679,114,1975,533,2295,154,2639,705,3007,200,3399,901,3815, %U A142883 252,4255,1121,4719,310,5207,1365,5719,374,6255,1633,6815,444,7399,1925,8007 %N A142883 a(n) = A142590(n)/3. %p A142883 A061037 := proc(n) 1/4-1/n^2 ; numer(%) ; end: A142590 := proc(n) A061037(2+3*n) ; end: %p A142883 A142883 := proc(n) A142590(n)/3 ; end: seq(A142883(n),n=0..120) ; # _R. J. Mathar_, Sep 07 2009 %K A142883 nonn,easy %O A142883 0,2 %A A142883 _Paul Curtz_, Sep 28 2008 %E A142883 Edited and extended by _R. J. Mathar_, Sep 07 2009