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 A094116 #5 Mar 30 2012 18:39:22 %S A094116 0,1,1,2,2,7,11,16,20,25,25,26,26,27,27,32,36,41,45,50,50,51,51,52,52, %T A094116 77,101,126,150,175,195,216,236,257,277,302,326,351,375,400,420,441, %U A094116 461,482,502,527,551,576,600,625,625,626,626,627,627,632,636,641,645,650 %N A094116 Partial sums of A093348. %F A094116 a(5^k)=(25^k-1)/12 %o A094116 (PARI) a(n)=sum(k=1,n,-sum(i=1,k-1,(-1)^i*5^valuation(i,5))) %K A094116 nonn %O A094116 1,4 %A A094116 _Benoit Cloitre_, May 03 2004