The On-Line Encyclopedia of Integer Sequences (OEIS)

The OEIS is supported by the many generous donors to the OEIS Foundation.

Revision History for A307690

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

A307690

Integers with only one prime factor and whose Euler's totient is a perfect biquadrate.
(history; published version)

#26 by Charles R Greathouse IV at Thu Sep 08 08:46:21 EDT 2022

PROG

(MAGMAMagma) [n:n in [1..10000000]| #PrimeDivisors(n) eq 1 and IsPower(EulerPhi(n), 4)]; // Marius A. Burtea, May 09 2019

Discussion

Thu Sep 08

08:46

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

#25 by N. J. A. Sloane at Sun May 12 08:24:28 EDT 2019

STATUS

proposed

approved

#24 by Marius A. Burtea at Thu May 09 16:08:53 EDT 2019

STATUS

editing

proposed

#23 by Marius A. Burtea at Thu May 09 15:51:07 EDT 2019

PROG

(MAGMA) [n:n in [1..10000000]| #PrimeDivisors(n) eq 1 and IsPower(EulerPhi(n), 4)]; // Marius A. Burtea, May 09 2019

STATUS

proposed

editing

#22 by Michel Marcus at Sun Apr 28 02:24:39 EDT 2019

STATUS

editing

proposed

Discussion

Sun Apr 28

03:15

Bernard Schott: Yes for the space, merci.

#21 by Michel Marcus at Sun Apr 28 02:24:06 EDT 2019

CROSSREFS

Subsequences: A013776 (2^(4*m+1)), A013806 (17^(4*m+1)), A037896 (primes of the form k^4 + 1).

STATUS

proposed

editing

Discussion

Sun Apr 28

02:24

Michel Marcus: you need a space here, otherwise it coud be interpreted as f(x)

#20 by Bernard Schott at Tue Apr 23 12:43:51 EDT 2019

STATUS

editing

proposed

#19 by Bernard Schott at Tue Apr 23 03:27:09 EDT 2019

CROSSREFS

Subsequence Intersection of A078164 and A246655.

Discussion

Tue Apr 23

03:27

Bernard Schott: Yes, you champion!

#18 by Michel Marcus at Tue Apr 23 03:20:28 EDT 2019

PROG

(PARI) isok(n) = (#factorisprimepower(n)[, 1] == 1) && ispower(eulerphi(n), 4); \\ Michel Marcus, Apr 23 2019

Discussion

Tue Apr 23

03:21

Michel Marcus: Subsequence of A078164, rather ?  Intersection of A078164 and A246655

#17 by Michel Marcus at Tue Apr 23 03:16:36 EDT 2019

PROG

(PARI) isok(n) = (#factor(n)[, 1] == 1) && ispower(eulerphi(n), 4); \\ Michel Marcus, Apr 23 2019

STATUS

proposed

editing