The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A248792

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A248792

Numbers n such that sigma(n) - 1 is a prime p.
(history; published version)

#24 by Charles R Greathouse IV at Thu Sep 08 08:46:10 EDT 2022

PROG

(MAGMAMagma) [n: n in[1..1000] | IsPrime(SumOfDivisors(n) - 1)]

Discussion

Thu Sep 08

08:46

OEIS Server: https://oeis.org/edit/global/2944

#23 by N. J. A. Sloane at Fri Jul 10 00:25:18 EDT 2015

STATUS

proposed

approved

#22 by Wesley Ivan Hurt at Thu Jul 09 21:54:53 EDT 2015

STATUS

editing

proposed

#21 by Wesley Ivan Hurt at Thu Jul 09 21:54:36 EDT 2015

MAPLE

with(numtheory): A248792:=n->`if`(isprime(sigma(n)-1), n, NULL): seq(A248792(n), n=1..200); # Wesley Ivan Hurt, Jul 09 2015

STATUS

proposed

editing

#20 by Robert Price at Thu Jul 09 21:35:35 EDT 2015

STATUS

editing

proposed

#19 by Robert Price at Thu Jul 09 21:35:32 EDT 2015

LINKS

OEIS Wiki, <a href="https://oeis.org/wiki/Cyclotomic Polynomials at x=n, n! and sigma(n)">Cyclotomic Polynomials at x=n, n! and sigma(n)</a>

STATUS

approved

editing

#18 by N. J. A. Sloane at Thu Nov 13 00:16:58 EST 2014

STATUS

proposed

approved

#17 by Michael De Vlieger at Fri Nov 07 09:47:08 EST 2014

STATUS

editing

proposed

#16 by Michael De Vlieger at Fri Nov 07 09:46:33 EST 2014

LINKS

Michael De Vlieger, <a href="/A248792/b248792.txt">Table of n, a(n) for n = 1..10000</a>

STATUS

proposed

editing

Discussion

Fri Nov 07

09:47

Michael De Vlieger: Added b-file generated by mma essentially the same as Vincenzo Librandi's.

#15 by Michel Marcus at Thu Nov 06 07:32:55 EST 2014

STATUS

editing

proposed