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A100005 Bisection of A001414. 0
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

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

LINKS

Table of n, a(n) for n=1..69.

EXAMPLE

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

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); (Deutsch)

CROSSREFS

Sequence in context: A219781 A215107 A084393 * A215457 A130159 A127314

Adjacent sequences:  A100002 A100003 A100004 * A100006 A100007 A100008

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Nov 20 2004

EXTENSIONS

More terms from Emeric Deutsch, Mar 10 2005

STATUS

approved

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Last modified April 23 02:10 EDT 2019. Contains 322380 sequences. (Running on oeis4.)