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 A100005 Bisection of A001414. 0

%I

%S 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,

%T 20,53,16,22,59,61,13,18,67,26,71,73,13,18,79,12,83,22,32,89,20,34,24,

%U 97,17,101,103,15,107,109,40,113,28,19,24,22,44,15,127,46,131,26,14,137

%N Bisection of A001414.

%C Integer log of (2n-1): sum of primes dividing 2n-1 (with repetition). - _Emeric Deutsch_, Mar 10 2005

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

%p 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

%K nonn,easy

%O 1,2

%A _N. J. A. Sloane_, Nov 20 2004

%E More terms from _Emeric Deutsch_, Mar 10 2005

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Last modified December 6 22:42 EST 2021. Contains 349567 sequences. (Running on oeis4.)