A023587 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A023587

a(n) = sum of distinct prime divisors of 2*prime(n)-1.

0

3, 5, 3, 13, 10, 5, 14, 37, 8, 22, 61, 73, 3, 22, 34, 15, 16, 11, 26, 50, 34, 157, 19, 62, 193, 70, 46, 74, 38, 8, 34, 32, 23, 277, 14, 50, 313, 18, 40, 31, 27, 19, 130, 23, 134, 397, 421, 94, 154, 457, 39, 56, 50, 170, 22, 15, 182, 541, 86, 31, 118, 21, 613, 26

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..64.

MATHEMATICA

Array[Plus@@First/@FactorInteger[2*Prime[ # ]-1]&, 5! ] (* Vladimir Joseph Stephan Orlovsky, Feb 28 2010 *)

CROSSREFS

Sequence in context: A023583 A266603 A121278 * A172003 A244801 A002586

Adjacent sequences: A023584 A023585 A023586 * A023588 A023589 A023590

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved