A023586 Exponent of least prime factor in prime factorization of 2*prime(n)-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

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