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 A064892 #4 Mar 30 2012 17:38:10 %S A064892 1,2,2,1,1,1,2,1,2,3,1,1,1,3,3,3,1,3,1,1,1,1,2,1,1,1,1,3,1,1,1,1,1,3, %T A064892 4,2,1,1,1,2,2,2,2,1,1,1,1,1,1,2,2,2,1,1,2,4,2,1,2,1,1,1,3,1,1,1,1,1, %U A064892 1,1,2,1,1,1,2,4,3,1,1,2,1,1,1,1,2,2,2,1,1,1,1,2,1,1,1,2,1,1,1,1,1,1,2,2,1 %N A064892 "Binary potency" of n-th prime p: length of shortest blocks of 0's inserted between the bits of p required to "dilute" it into a nonprime. %C A064892 Note that the +2 dilution of 3 is not the +1 dilution of 5! %e A064892 2nd prime = 3 = 11 -> 0101 = 5 -> 001001 = 9, so a(2) = 2; 3rd prime = 5 = 101 -> 010001 = 17 -> 001000001 = 65, so a(3) = 2 %Y A064892 A000040, A064891, A064893. %K A064892 base,easy,nonn %O A064892 1,2 %A A064892 _Marc LeBrun_, Oct 10 2001