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A100029 Bisection of A008472. 0
0, 3, 5, 7, 3, 11, 13, 8, 17, 19, 10, 23, 5, 3, 29, 31, 14, 12, 37, 16, 41, 43, 8, 47, 7, 20, 53, 16, 22, 59, 61, 10, 18, 67, 26, 71, 73, 8, 18, 79, 3, 83, 22, 32, 89, 20, 34, 24, 97, 14, 101, 103, 15, 107, 109, 40, 113, 28, 16, 24, 11, 44, 5, 127, 46, 131, 26, 8, 137, 139, 50, 24 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The sum of the distinct primes dividing 2n-1. - Emeric Deutsch, Mar 11 2005

LINKS

Table of n, a(n) for n=1..72.

EXAMPLE

a(23)=8 because 45=3^2*5 and 3+5=8.

MAPLE

with(numtheory): a:=proc(n) local b: b:=convert(factorset(2*n-1), list): add(b[j], j=1..nops(b)) end: seq(a(n), n=1..80); (Deutsch)

MATHEMATICA

Join[{0}, Total[Transpose[FactorInteger[#]][[1]]]&/@(2*Range[2, 80]-1)] (* Harvey P. Dale, Aug 05 2015 *)

CROSSREFS

Sequence in context: A076565 A286517 A199423 * A099984 A130141 A130142

Adjacent sequences:  A100026 A100027 A100028 * A100030 A100031 A100032

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Nov 20 2004

EXTENSIONS

More terms from Emeric Deutsch, Mar 11 2005

STATUS

approved

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Last modified February 25 16:14 EST 2018. Contains 299653 sequences. (Running on oeis4.)