The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A139571 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A139571

Numbers with 31 divisors.
(history; published version)

#23 by Susanna Cuyler at Thu May 06 08:24:17 EDT 2021

STATUS

proposed

approved

#22 by Michel Marcus at Thu May 06 01:12:30 EDT 2021

STATUS

editing

proposed

#21 by Michel Marcus at Thu May 06 01:12:25 EDT 2021

CROSSREFS

Cf. A073915, A122971, A137493 (30 divs), A175742 (32 divs).

STATUS

proposed

editing

#20 by Jon E. Schoenfield at Thu May 06 01:10:12 EDT 2021

STATUS

editing

proposed

#19 by Jon E. Schoenfield at Thu May 06 01:10:11 EDT 2021

COMMENTS

Start of 31st row of A073915. [From _- _R. J. Mathar_, Jun 27 2009, Jun 28 2009]

FORMULA

a(n) = A000040(n)^(31-1) = A000040(n)^30.

a(n) = A122971(A000040(n)). - R. J. Mathar, Jun 27 2009

STATUS

approved

editing

#18 by R. J. Mathar at Tue Aug 13 15:31:32 EDT 2019

STATUS

editing

approved

#17 by R. J. Mathar at Tue Aug 13 15:31:22 EDT 2019

CROSSREFS

Cf. A000005, A000040, A001248, A030514, A030516, A030629, A030631, A030635, A030637, A137486, A137492, A139572, A139573.

Cf. A137493 (30 divs), A175742 (32 divs).

EXTENSIONS

One more term from R. J. Mathar, Jun 27 2009

Length restrictions in A073915 emphasized by R. J. Mathar, Jun 28 2009

STATUS

approved

editing

#16 by Charles R Greathouse IV at Sun Jun 19 02:51:28 EDT 2016

STATUS

editing

approved

#15 by Charles R Greathouse IV at Sun Jun 19 02:51:24 EDT 2016

FORMULA

a(n)=A122971(A000040(n)). [From _- _R. J. Mathar_, Jun 27 2009]

PROG

(PARI) a(n)=prime(n)^30 \\ Charles R Greathouse IV, Jun 19 2016

KEYWORD

nonn,easy

STATUS

approved

editing

#14 by Charles R Greathouse IV at Thu Nov 21 13:07:21 EST 2013

MATHEMATICA

Prime[Range[11]]^30 (* From _Vladimir Joseph Stephan Orlovsky, _, May 05 2011 *)

Discussion

Thu Nov 21

13:07

OEIS Server: https://oeis.org/edit/global/2063