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A023586 Exponent of least prime factor in prime factorization of 2*prime(n)-1. 1
1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 1, 4, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 3, 1, 1, 2, 2, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 3, 1, 1, 1, 1, 1, 1, 2, 1, 3, 4, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 3, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 2, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

First differs from A023584 at n = 56. - Sean A. Irvine, Jun 07 2019

LINKS

Sean A. Irvine, Table of n, a(n) for n = 1..1000

PROG

(PARI) a(n) = factor(2*prime(n)-1)[1, 2]; \\ Michel Marcus, Jun 08 2019

CROSSREFS

Cf. A023854.

Sequence in context: A307223 A321787 A331596 * A023584 A015182 A057559

Adjacent sequences:  A023583 A023584 A023585 * A023587 A023588 A023589

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

Title corrected by Sean A. Irvine, Jun 07 2019

STATUS

approved

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Last modified May 14 22:40 EDT 2021. Contains 343909 sequences. (Running on oeis4.)