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.

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, 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, 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

Offset: 1

Author

Marc LeBrun, Oct 10 2001

Keywords

• base
• easy
• nonn

Comments

Note that the +2 dilution of 3 is not the +1 dilution of 5!

Examples

			2nd prime = 3 = 11 -> 0101 = 5 -> 001001 = 9, so a(2) = 2; 3rd prime = 5 = 101 -> 010001 = 17 -> 001000001 = 65, so a(3) = 2
		

Crossrefs

A000040, A064891, A064893.