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Revision History for A123995 (Bold, blue-underlined text is an addition; faded, red-underlined text is a deletion.)

Showing entries 1-10 | older changes
First occurrence of prime gaps which are perfect powers.
(history; published version)
#19 by N. J. A. Sloane at Thu Oct 28 12:37:08 EDT 2021
LINKS

Thomas R. Nicely, <a href="https://faculty.lynchburg.edu/~nicely/gaps/gaplist.html">First occurrence prime gaps</a> [For local copy see A000101].

Discussion
Thu Oct 28
12:37
OEIS Server: https://oeis.org/edit/global/2920
#18 by N. J. A. Sloane at Mon Oct 25 23:56:53 EDT 2021
LINKS

Thomas R. Nicely, <a href="httphttps://wwwfaculty.trnicelylynchburg.netedu/~nicely/gaps/gaplist.html">First occurrence prime gaps</a>.

Discussion
Mon Oct 25
23:56
OEIS Server: https://oeis.org/edit/global/2919
#17 by M. F. Hasler at Fri Oct 19 17:24:03 EDT 2018
STATUS

editing

approved

#16 by M. F. Hasler at Fri Oct 19 17:22:05 EDT 2018
NAME

Smallest prime p such that the gap between p and the next prime, q, is a perfect power (as in A001597).

First occurrence of prime gaps which are perfect powers.

STATUS

approved

editing

Discussion
Fri Oct 19
17:24
M. F. Hasler: Proposed & approved new name, cf. History
#15 by N. J. A. Sloane at Thu Oct 18 21:12:38 EDT 2018
STATUS

editing

approved

#14 by N. J. A. Sloane at Thu Oct 18 21:12:27 EDT 2018
NAME

Smallest prime p such that the gap between p and the next prime, q, is a perfect power (as in A001597).

COMMENTS

The old definition is was confusing - there is only one such prime. Also, it is not meant that for each term of A001597 (perfect powers), the smallest prime followed by that gap is listed. What is meant was: primes p such that nextprime(p)-p is an element of A001597 (or A075090: even perfect powers, for n > 1), and p is the smallest prime followed by this gap. - M. F. Hasler, Oct 18 2018

CROSSREFS

Cf. A080370, A113472, A000230, A001597, (perfect powers), A075090, A002386, A138198.

EXTENSIONS

Better definition from M. F. Hasler, Oct 18 2018

STATUS

proposed

editing

Discussion
Thu Oct 18
21:12
N. J. A. Sloane: Edited
#13 by Michel Marcus at Thu Oct 18 12:50:07 EDT 2018
STATUS

editing

proposed

Discussion
Thu Oct 18
14:46
Peter Luschny: Your rewording is fine for me!
#12 by Michel Marcus at Thu Oct 18 12:50:04 EDT 2018
MATHEMATICA

NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ@k, k++ ]; k]; perfectPowerQ[x_] := GCD @@ Last /@ FactorInteger@x > 1; dd = {1}; pp = {2}; qq = {3}; p = 3; Do[q = NextPrim@p; d = q - p; If[perfectPowerQ@d && ! MemberQ[dd, d], Print@q; AppendTo[pp, p]; AppendTo[dd, d]]; p = q, {n, 10^7}]; pp (* Robert G. Wilson v , Nov 03 2006 *)

EXTENSIONS

Edited and extended by Robert G. Wilson v , Nov 03 2006, and corrected Nov 04 2006

STATUS

proposed

editing

#11 by M. F. Hasler at Thu Oct 18 11:30:18 EDT 2018
STATUS

editing

proposed

#10 by M. F. Hasler at Thu Oct 18 11:30:12 EDT 2018
COMMENTS

A138198 is a subsequence. - M. F. Hasler, Oct 18 2018

STATUS

proposed

editing