A100005 Bisection of A001414.

0, 3, 5, 7, 6, 11, 13, 8, 17, 19, 10, 23, 10, 9, 29, 31, 14, 12, 37, 16, 41, 43, 11, 47, 14, 20, 53, 16, 22, 59, 61, 13, 18, 67, 26, 71, 73, 13, 18, 79, 12, 83, 22, 32, 89, 20, 34, 24, 97, 17, 101, 103, 15, 107, 109, 40, 113, 28, 19, 24, 22, 44, 15, 127, 46, 131, 26, 14, 137

Offset: 1

Author

N. J. A. Sloane, Nov 20 2004

Keywords

• nonn
• easy

Comments

Integer log of (2n-1): sum of primes dividing 2n-1 (with repetition). - Emeric Deutsch, Mar 10 2005

Examples

			a(23)=11 because 45=3^2*5^1 and 2*3+1*5=11.
		

Programs

Maple

with(numtheory): a:=proc(n) local b: b:=op(2,ifactors(n)): sum(b[j][1]*b[j][2],j=1..nops(b)): end: seq(a(2*n-1),n=1..78); # Emeric Deutsch, Mar 10 2005

Extensions

More terms from Emeric Deutsch, Mar 10 2005