A100030 Bisection of A008472.

2, 2, 5, 2, 7, 5, 9, 2, 5, 7, 13, 5, 15, 9, 10, 2, 19, 5, 21, 7, 12, 13, 25, 5, 7, 15, 5, 9, 31, 10, 33, 2, 16, 19, 14, 5, 39, 21, 18, 7, 43, 12, 45, 13, 10, 25, 49, 5, 9, 7, 22, 15, 55, 5, 18, 9, 24, 31, 61, 10, 63, 33, 12, 2, 20, 16, 69, 19, 28, 14, 73, 5, 75, 39, 10, 21, 20, 18, 81, 7, 5

Offset

1,1

Comments

The sum of the distinct primes dividing 2n. - Emeric Deutsch, Mar 11 2005

Links

Table of n, a(n) for n=1..81.

Example

a(6)=5 because 12 = 2^2*3 and 2+3 = 5.

Maple

with(numtheory): a:=proc(n) local b: b:=convert(factorset(2*n), list): add(b[j], j=1..nops(b)) end: seq(a(n), n=1..90); # Emeric Deutsch, Mar 11 2005

Crossrefs

Sequence in context: A029648 A126103 A316895 * A029603 A204202 A336924

Adjacent sequences: A100027 A100028 A100029 * A100031 A100032 A100033

Keyword

nonn,easy

Author

N. J. A. Sloane, Nov 20 2004

Extensions

More terms from Emeric Deutsch, Mar 11 2005

Status

approved