The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A256385

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A256385

Numbers n such that 2n^2+2n+1, 3n^2+6n+5, 6n^2+30n+55 are all composite.
(history; published version)

#34 by Charles R Greathouse IV at Thu Sep 08 08:46:11 EDT 2022

PROG

(MAGMAMagma) [n: n in [0..130] | not IsPrime(2*n^2+2*n+1) and not IsPrime(3*n^2+6*n+5) and not IsPrime(6*n^2+30*n+55)]; // Vincenzo Librandi, Apr 01 2015

Discussion

Thu Sep 08

08:46

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

#33 by Harvey P. Dale at Fri Jul 16 10:27:09 EDT 2021

STATUS

editing

approved

#32 by Harvey P. Dale at Fri Jul 16 10:27:05 EDT 2021

STATUS

proposed

editing

#31 by Harvey P. Dale at Fri Jul 16 10:26:40 EDT 2021

STATUS

editing

proposed

Discussion

Fri Jul 16

10:28

Joerg Arndt: 1421 sequences contain "Requires Mathematica version", so let's purge those (only) opportunistically.

#30 by Harvey P. Dale at Fri Jul 16 10:26:33 EDT 2021

MATHEMATICA

Select[Range[200], AllTrue[{2#^2+2#+1, 3#^2+6#+5, 6#^2+30#+55}, CompositeQ]&] (* Requires Mathematica version 10 or later *) (* __Harvey P. Dale_, Jul 15 2021 *)

#29 by Harvey P. Dale at Thu Jul 15 15:55:05 EDT 2021

MATHEMATICA

Select[Range[200], AllTrue[{2#^2+2#+1, 3#^2+6#+5, 6#^2+30#+55}, CompositeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jul 15 2021 *)

STATUS

approved

editing

Discussion

Fri Jul 16

02:03

Joerg Arndt: version 10 of mathca appeared 2014, so maybe that remark is not needed?

10:25

Harvey P. Dale: I agree and therefore have deleted it. I put similar language in quite a few other sequences and would be perfectly happy having it deleted in each of them. I don't know how best to do that, however, and would be glad if someone else could take on that effort.

#28 by Bruno Berselli at Fri Apr 03 18:18:08 EDT 2015

STATUS

proposed

approved

#27 by Vladimir Shevelev at Fri Apr 03 14:58:12 EDT 2015

STATUS

editing

proposed

#26 by Vladimir Shevelev at Fri Apr 03 14:57:21 EDT 2015

CROSSREFS

Cf. A000290, A001844, A005918, A027865, A256463, A089306, A077654, A256546, A256581.

STATUS

approved

editing

#25 by N. J. A. Sloane at Fri Apr 03 12:59:02 EDT 2015

STATUS

proposed

approved