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 A087439 #5 Jun 13 2015 00:51:08 %S A087439 1,5,22,98,451,2135,10312,50468,249061,1235465,6147802,30650438, %T A087439 152986471,764135195,3818284492,19084248008,95399716681,476934013325, %U A087439 2384476356382,11921800651178,59607259863691,298031069141855 %N A087439 Expansion of (1-4x)/((1-x)(1-3x)(1-5x)). %C A087439 Partial sums of A081186. The sequence 0,1,5,22,.. is given by 5^n/8+3^n/4-3/8. Binomial transform of A087440. %H A087439 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (9,-23,15). %F A087439 a(n)=5*5^n/8+3*3^n/4-3/8. %K A087439 easy,nonn %O A087439 0,2 %A A087439 _Paul Barry_, Sep 03 2003