The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A023591 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A023591

Greatest exponent in prime-power factorization of 2*prime(n)+1.
(history; published version)

#12 by Joerg Arndt at Mon Sep 09 02:40:46 EDT 2024

STATUS

reviewed

approved

#11 by Michel Marcus at Mon Sep 09 00:46:24 EDT 2024

STATUS

proposed

reviewed

#10 by Amiram Eldar at Mon Sep 09 00:26:19 EDT 2024

STATUS

editing

proposed

#9 by Amiram Eldar at Mon Sep 09 00:03:08 EDT 2024

FORMULA

a(n) = A051903(A072055(n)). - Amiram Eldar, Sep 09 2024

MATHEMATICA

a[n_] := Max[FactorInteger[2*Prime[n] + 1][[;; , 2]]]; Array[a, 100] (* Amiram Eldar, Sep 09 2024 *)

STATUS

approved

editing

#8 by Susanna Cuyler at Tue Apr 20 22:42:34 EDT 2021

STATUS

proposed

approved

#7 by Michel Marcus at Tue Apr 20 12:26:03 EDT 2021

STATUS

editing

proposed

#6 by Michel Marcus at Tue Apr 20 12:25:59 EDT 2021

PROG

(PARI) a(n) = vecmax(factor(2*prime(n)+1)[, 2]); \\ Michel Marcus, Apr 20 2021

STATUS

approved

editing

#5 by R. J. Mathar at Wed Jul 08 06:00:20 EDT 2015

STATUS

editing

approved

#4 by R. J. Mathar at Wed Jul 08 06:00:02 EDT 2015

NAME

Greatest exponent in prime-power factorization of 2*pprime(n)+1.

MAPLE

A023591 := proc(n)

A051903(2*ithprime(n)+1) ;

end proc: # R. J. Mathar, Jul 08 2015

CROSSREFS

Cf. A051903, A072055.

STATUS

approved

editing

#3 by Russ Cox at Fri Mar 30 18:55:53 EDT 2012

AUTHOR

Clark Kimberling (ck6(AT)evansville.edu)

Clark Kimberling

Discussion

Fri Mar 30

18:55

OEIS Server: https://oeis.org/edit/global/285