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A023580 Sum of distinct prime divisors of prime(n)+3. 0
5, 5, 2, 7, 9, 2, 7, 13, 15, 2, 19, 7, 13, 25, 7, 9, 33, 2, 14, 39, 21, 43, 45, 25, 7, 15, 55, 18, 9, 31, 20, 69, 14, 73, 21, 20, 7, 85, 24, 13, 22, 25, 99, 9, 7, 103, 109, 115, 30, 31, 61, 13, 63, 129, 20, 28, 19, 139, 14, 73, 26, 39, 38, 159, 81, 7, 169, 24, 14 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

a(n) = A008472(A113935(n)). - Michel Marcus, May 05 2021

MATHEMATICA

Total[First/@FactorInteger[#]]&/@(Prime@Range@100+3) (* Giorgos Kalogeropoulos, May 05 2021 *)

PROG

(Python)

from sympy import primefactors, prime

def a(n): return sum(primefactors(prime(n) + 3))

print([a(n) for n in range(1, 70)]) # Michael S. Branicky, May 05 2021

CROSSREFS

Cf. A008472, A113935.

Sequence in context: A019602 A153839 A322159 * A021648 A287746 A128006

Adjacent sequences:  A023577 A023578 A023579 * A023581 A023582 A023583

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified June 21 06:24 EDT 2021. Contains 345358 sequences. (Running on oeis4.)