The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A115973 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A115973

Number of distinct prime factors of p^p + 1 where p is prime(n).
(history; published version)

#27 by Michael De Vlieger at Tue Mar 05 16:31:36 EST 2024

STATUS

proposed

approved

#26 by Michel Marcus at Tue Mar 05 12:26:05 EST 2024

STATUS

editing

proposed

#25 by Michel Marcus at Tue Mar 05 12:25:56 EST 2024

MATHEMATICA

f[n_] := Length@ FactorInteger[Prime[n]^Prime[n] + 1]; Array[f, 20] - _(* _Robert G. Wilson v_, Apr 06 2006 *)

PROG

(PARI) { for(n=1, 20, p = prime(n); d = factor(p^p+1); dec=matsize(d); print1(dec[1], ", "); ); } - _\\ _R. J. Mathar_, Mar 29 2006

STATUS

approved

editing

#24 by Amiram Eldar at Fri Aug 04 05:06:59 EDT 2023

STATUS

reviewed

approved

#23 by Joerg Arndt at Fri Aug 04 01:47:50 EDT 2023

STATUS

proposed

reviewed

#22 by Sean A. Irvine at Fri Aug 04 01:06:25 EDT 2023

STATUS

editing

proposed

#21 by Sean A. Irvine at Fri Aug 04 01:06:11 EDT 2023

DATA

1, 2, 3, 3, 6, 5, 3, 5, 8, 7, 7, 7, 6, 8, 10, 8, 9, 8, 7, 8, 4, 7, 12, 6, 8, 7, 12, 9, 11, 6, 9, 7, 17, 9, 9

EXTENSIONS

a(33), -a(34) from Hugo Pfoertner, Aug 07 2019

a(28) corrected by Sean A. Irvine, Aug 04 2023

STATUS

approved

editing

#20 by Alois P. Heinz at Sat Jul 08 18:41:35 EDT 2023

STATUS

proposed

approved

#19 by Dario Alpern at Sat Jul 08 18:32:59 EDT 2023

STATUS

editing

proposed

#18 by Dario Alpern at Sat Jul 08 18:32:39 EDT 2023

LINKS

Dario Alejandro Alpern, <a href="httphttps://www.alpertron.com.ar/ECM.HTM">Factorization using the Elliptic Curve Method</a>

STATUS

approved

editing

Discussion

Sat Jul 08

18:32

Dario Alpern: Changed http to https. factordb does not support https.