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 A093555 #5 Mar 30 2012 18:50:43 %S A093555 0,0,0,0,1,0,0,1,1,2,0,1,3,1,1,1,1,0,4,3,1,3,1,3,5,1,2,2,3,1,5,1,1,5, %T A093555 7,3,1,3,1,3,7,3,1,0,2,5,1,9,1,5,5,3,1,3,5,1,9,1,3,1,11,11,3,1,3,5,1, %U A093555 1,7,4,0,5,5,1,5,3,1,5,3,13,3,1,3,13,5,5,3,1,3,5,1,5,5,5,3,5,7,3,7,9 %N A093555 Number of non-prime-powers between consecutive prime-powers. %C A093555 a(n) = A000961(n+1)-A000961(n)-1 = A057820(n)-1. %Y A093555 Cf. A046933. %K A093555 nonn %O A093555 1,10 %A A093555 _Reinhard Zumkeller_, Jul 09 2004