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Revision History for A138407

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A138407

a(n) = p^4*(p-1), where p = prime(n).
(history; published version)

#24 by Joerg Arndt at Tue Nov 22 02:33:44 EST 2022

STATUS

reviewed

approved

#23 by Michel Marcus at Tue Nov 22 02:04:08 EST 2022

STATUS

proposed

reviewed

#22 by Amiram Eldar at Tue Nov 22 01:32:12 EST 2022

STATUS

editing

proposed

#21 by Amiram Eldar at Tue Nov 22 00:58:28 EST 2022

LINKS

<a href="/index/Pri#prime_powers">Index to sequences related to prime powers</a>.

#20 by Amiram Eldar at Tue Nov 22 00:58:08 EST 2022

FORMULA

From Amiram Eldar, Nov 22 2022: (Start)

a(n) = prime(n)^5 - prime(n)^4 = A050997(n) - A030514(n).

Product_{n>=1} (1 - 1/a(n)) = A065416. (End)

CROSSREFS

Cf. A000010, A030514, A050997, A065416.

STATUS

approved

editing

#19 by Charles R Greathouse IV at Thu Sep 08 08:45:33 EDT 2022

PROG

(MAGMAMagma) [NthPrime((n))^5 - NthPrime((n))^4: n in [1..30] ]; // Vincenzo Librandi, Jun 17 2011

Discussion

Thu Sep 08

08:45

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

#18 by Joerg Arndt at Fri Sep 14 05:15:14 EDT 2018

STATUS

proposed

approved

#17 by Jon E. Schoenfield at Thu Sep 13 21:22:18 EDT 2018

STATUS

editing

proposed

Discussion

Fri Sep 14

02:25

Joerg Arndt: Looks correct to me: 
vector(22,n,eulerphi(prime(n)^5))
[16, 162, 2500, 14406, 146410, 342732, 1336336, 2345778, 6156502, 19803868, 27705630, 67469796, 113030440, 143589642, 224465326, 410305012, 702806938, 830750460, 1329973986, 1778817670, 2044673352, 3038106318]

04:23

Jon E. Schoenfield: I'm sorry, I misread the "A000010" as "A000040" -- please disregard my comment.

#16 by Jon E. Schoenfield at Thu Sep 13 21:22:07 EDT 2018

PROG

(MAGMA) [NthPrime((n))^5 - NthPrime((n))^4: n in [1..30] ]; // _Vincenzo Librandi, _, Jun 17 2011

STATUS

approved

editing

Discussion

Thu Sep 13

21:22

Jon E. Schoenfield: Formula entry is obviously wrong.

#15 by R. J. Mathar at Sun Oct 15 09:48:13 EDT 2017

STATUS

editing

approved