The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A002540 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A002540

Increasing gaps between prime-powers.
(history; published version)

#55 by OEIS Server at Fri Oct 18 08:58:38 EDT 2024

LINKS

Jan Kristian Haugland, <a href="/A002540/b002540_1.txt">Table of n, a(n) for n = 1..87</a> (terms 1..79 from Donovan Johnson). The extra terms are copied from A002386 as the associated prime gaps do not contain any prime powers.

#54 by Charles R Greathouse IV at Fri Oct 18 08:58:38 EDT 2024

STATUS

proposed

approved

Discussion

Fri Oct 18

08:58

OEIS Server: Installed new b-file as b002540.txt.  Old b-file is now b002540_1.txt.

#53 by Hugo Pfoertner at Fri Oct 18 08:48:14 EDT 2024

STATUS

editing

proposed

Discussion

Fri Oct 18

08:58

Charles R Greathouse IV: Great, thanks for keeping this up to date!

#52 by Hugo Pfoertner at Fri Oct 18 08:45:15 EDT 2024

DATA

1, 5, 13, 19, 32, 53, 89, 139, 199, 293, 887, 1129, 1331, 5591, 8467, 9551, 15683, 19609, 31397, 155921, 360653, 370261, 492113, 1349533, 1357201, 2010733, 4652353, 17051707, 20831323, 47326693, 122164747, 189695659, 191912783, 387096133, 436273009, 1294268491

LINKS

EXTENSIONS

a(80)-a(87) and b-file from Jan Kristian Haugland, Oct 18 2024: The extra terms are copied from A002386 as the associated prime gaps do not contain any prime powers.

STATUS

proposed

editing

Discussion

Fri Oct 18

08:48

Hugo Pfoertner: Donovan Johnson already had found all terms in DATA, so no need to use EXTENSION field. Changes to b-file are only recorded with the b-file.

#51 by Jan Kristian Haugland at Fri Oct 18 08:03:19 EDT 2024

STATUS

editing

proposed

#50 by Jan Kristian Haugland at Fri Oct 18 08:01:20 EDT 2024

LINKS

Donovan Johnson, Jan Kristian Haugland, <a href="/A002540/b002540_1.txt">Table of n, a(n) for n = 1..87</a> (terms 1..79</a> from Donovan Johnson)

EXTENSIONS

a(28)-a(79) and b-file from Donovan Johnson, Nov 14 2008

a(80)-a(87) and b-file from Jan Kristian Haugland, Oct 18 2024: The extra terms are copied from A002386 as the associated prime gaps do not contain any prime powers.

STATUS

approved

editing

#49 by Harvey P. Dale at Tue Aug 20 10:49:01 EDT 2024

STATUS

editing

approved

#48 by Harvey P. Dale at Tue Aug 20 10:48:53 EDT 2024

MATHEMATICA

Join[{1}, Rest[Module[{nn=5*10^6, pps}, pps=Select[Range[nn], PrimePowerQ]; DeleteDuplicates[ Thread[{Most[ pps], Differences[ pps]}], GreaterEqual[ #1[[2]], #2[[2]]]&]][[;; , 1]]]] (* The program generates the first 27 terms of the sequence. *) (* Harvey P. Dale, Aug 20 2024 *)

STATUS

approved

editing

#47 by Joerg Arndt at Mon Dec 12 01:32:51 EST 2022

STATUS

reviewed

approved

#46 by Michel Marcus at Mon Dec 12 01:19:42 EST 2022

STATUS

proposed

reviewed