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A210934 Sum of prime factors of prime(n)+1 (counted with multiplicity). 3
3, 4, 5, 6, 7, 9, 8, 9, 9, 10, 10, 21, 12, 15, 11, 11, 12, 33, 21, 12, 39, 13, 14, 13, 16, 22, 19, 13, 18, 24, 14, 18, 28, 16, 15, 25, 81, 45, 16, 34, 15, 22, 15, 99, 19, 16, 57, 17, 26, 30, 21, 16, 24, 17, 48, 20, 16, 25, 141, 52, 75, 19, 22, 22, 159, 58, 87 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

From an idea of Michael B. Porter.

LINKS

Paolo P. Lava, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A001414(A008864(n)). - Michel Marcus, Oct 05 2013

EXAMPLE

prime(8) = 19, and 19+1 = 20 = 2*2*5, so a(8) = 2+2+5 = 9.

MAPLE

with(numtheory);

P:=proc(i)

local a, k, n;

for n from 1 to i do

  a:=ifactors(ithprime(n)+1)[2]; print(add(a[k][1]*a[k][2], k=1..nops(a)));

od; end:

CROSSREFS

Cf. A023508, A023514, A210936

Sequence in context: A037350 A014615 A144046 * A194276 A184336 A183300

Adjacent sequences:  A210931 A210932 A210933 * A210935 A210936 A210937

KEYWORD

nonn

AUTHOR

Paolo P. Lava, Mar 30 2012

STATUS

approved

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Last modified August 16 23:58 EDT 2018. Contains 313809 sequences. (Running on oeis4.)