The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A243368 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A243368

Primes p such that q = p^2 + 10 and q^2 + 10 are also prime.
(history; published version)

#13 by N. J. A. Sloane at Thu Jun 05 01:42:32 EDT 2014

STATUS

proposed

approved

#12 by Michel Marcus at Wed Jun 04 12:18:36 EDT 2014

STATUS

editing

proposed

Discussion

Wed Jun 04

12:50

Zak Seidov: OK, thx

#11 by Michel Marcus at Wed Jun 04 12:16:19 EDT 2014

COMMENTS

Both This is a subsequence of A243367 where both p and p^2 + 10 are terms in A243367:, see examples.

p = a(1) = 7 = A243367(2) and p^2 + 10 = 59 = A243367(7),

p = a(2) = 13 = A243367(4) and p^2 + 10 = 179 = A243367(15).

EXAMPLE

p = a(1) = 7 = A243367(2) and p^2 + 10 = 59 = A243367(7),

p = a(2) = 13 = A243367(4) and p^2 + 10 = 179 = A243367(15).

STATUS

proposed

editing

Discussion

Wed Jun 04

12:18

Michel Marcus: I thought 2nd and 3rd line of comments could go to examples. I wanted to add 'subsequence' and I tried to link both. Hope this looks OK. Amend if you see a better way.

#10 by Zak Seidov at Wed Jun 04 11:12:54 EDT 2014

STATUS

editing

proposed

#9 by Zak Seidov at Wed Jun 04 11:12:47 EDT 2014

COMMENTS

p = a(1) = 7 = A243367(2) and p^2 + 10 = 59 = A243367(7),

STATUS

proposed

editing

#8 by Colin Barker at Wed Jun 04 10:51:11 EDT 2014

STATUS

editing

proposed

#7 by Colin Barker at Wed Jun 04 10:50:34 EDT 2014

DATA

7, 13, 211, 601, 743, 2281, 2659, 2897, 3109, 3361, 4271, 4397, 6173, 7321, 7351, 8807, 8863, 11941, 12377, 13033, 13159, 13999, 14449, 14951, 20117, 20161, 20551, 22709, 24109, 25733, 27299, 27749, 29989, 30071, 31123, 31541, 33347, 33377, 33487, 33629

PROG

(PARI) s=[]; forprime(p=2, 100000, q=p^2+10; if(isprime(q)&&isprime(q^2+10), s=concat(s, p))); s \\ Colin Barker, Jun 04 2014

EXTENSIONS

More terms from Colin Barker, Jun 04 2014

STATUS

proposed

editing

#6 by Zak Seidov at Wed Jun 04 10:02:24 EDT 2014

STATUS

editing

proposed

#5 by Zak Seidov at Wed Jun 04 10:00:26 EDT 2014

DATA

59, 179, 44531, 361211, 552059, 5202971, 7070291, 8392619, 9665891, 11296331, 18241451, 19333619, 38105939, 53597051, 540372117, 13, 211, 601, 743, 2281, 2659, 2897, 3109, 3361, 4271, 4397, 6173, 7321, 7351

COMMENTS

All terms are congruent to {11,59} modulo 60.

Subsequence of A243367: a(1) = 59 = A182475(7), a(15) = 54037211 = A182475(159).

Both p and p^2 + 10 are terms in A243367:

p = a(1) = A243367(2) and p^2 + 10 = 59 = A243367(7),

p = a(2) = 13 = A243367(4) and p^2 + 10 = 179 = A243367(15).

STATUS

proposed

editing

Discussion

Wed Jun 04

10:02

Zak Seidov: Data and comments corrected by Michel Marcus, thx!!
Worth  including in Extension!

#4 by Zak Seidov at Wed Jun 04 01:21:09 EDT 2014

STATUS

editing

proposed

Discussion

Wed Jun 04

03:01

Michel Marcus: Zak, I think you gave the list of q's in data, instead of the list of p's.