Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #4 Mar 30 2012 17:38:10
%S 0,1,2,0,2,0,1,0,0,0,1,0,1,0,0,0,2,0,1,0,0,0,2,0,0,0,0,0,3,0,1,0,0,0,
%T 0,0,1,0,0,0,1,0,3,0,0,0,3,0,0,0,0,0,3,0,0,0,0,0,1,0,3,0,0,0,0,0,1,0,
%U 0,0,1,0,1,0,0,0,0,0,1,0,0,0,2,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,1,0,1,0,0
%N "Binary potency" of n: length of shortest blocks of 0's inserted between the bits of n required to "dilute" it into a nonprime.
%C Zero for all nonprime n. Note that the +2 dilution of 3 is not the +1 dilution of 5!
%e 3 = 11 -> 0101 = 5 -> 001001 = 9, so a(3) = 2; 5 = 101 -> 010001 = 17 -> 001000001 = 65, so a(5) = 2
%Y Cf. A000040, A064892, A064893.
%K base,easy,nonn
%O 1,3
%A _Marc LeBrun_, Oct 10 2001