The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A107145 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A107145

Primes of the form x^2 + 40y^2.
(history; published version)

#12 by N. J. A. Sloane at Sun Jun 08 14:50:21 EDT 2014

STATUS

editing

approved

#11 by N. J. A. Sloane at Sun Jun 08 14:50:17 EDT 2014

LINKS

N. J. A. Sloane et al., <a href="https://oeis.org/wiki/Binary_Quadratic_Forms_and_OEIS">Binary Quadratic Forms and OEIS</a> (Index to related sequences, programs, references)

STATUS

approved

editing

#10 by N. J. A. Sloane at Wed Jun 04 15:39:49 EDT 2014

MATHEMATICA

QuadPrimes[1, 0, 40, 10000] (* see A106856 *) Note: the original QuadPrimes had a bug which could sometimes give wrong answers. This sequence should be checked. - _N. J. A. Sloane_, Jun 04 2014

Discussion

Wed Jun 04

15:39

OEIS Server: https://oeis.org/edit/global/2225

#9 by Bruno Berselli at Tue Jul 24 07:02:37 EDT 2012

STATUS

proposed

approved

#8 by Vincenzo Librandi at Tue Jul 24 02:12:00 EDT 2012

STATUS

editing

proposed

#7 by Vincenzo Librandi at Tue Jul 24 02:11:55 EDT 2012

LINKS

Vincenzo Librandi, <a href="/A107145/b107145.txt">Table of n, a(n) for n = 1..1000</a>

PROG

(MAGMA) [ p: p in PrimesUpTo(3000) | p mod 40 in {1, 9} ]; // Vincenzo Librandi, Jul 24 2012

STATUS

approved

editing

#6 by Russ Cox at Fri Mar 30 17:22:39 EDT 2012

FORMULA

The primes are congruent to {1, 9} (mod 40). - _T. D. Noe (noe(AT)sspectra.com), _, Apr 29 2008

AUTHOR

_T. D. Noe (noe(AT)sspectra.com), _, May 13 2005

Discussion

Fri Mar 30

17:22

OEIS Server: https://oeis.org/edit/global/120

#5 by T. D. Noe at Tue Apr 19 12:25:06 EDT 2011

STATUS

proposed

approved

#4 by T. D. Noe at Tue Apr 19 12:25:00 EDT 2011

MATHEMATICA

f[x_, y_]:=x^2+40*y^2; lst={}; Do[Do[p=f[x, y]; If[PrimeQ[p]&&p>0, AppendTo[lst, p]], {y, -4!, 3*4!}], {x, -4!, 3*4!}]; Take[Union[lst], 90] [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Jun 30 2009]

STATUS

approved

proposed

Discussion

Tue Apr 19

12:25

T. D. Noe: Removed program having too many magic constants.

#3 by N. J. A. Sloane at Tue Jun 01 03:00:00 EDT 2010

MATHEMATICA

QuadPrimes[1, 0, 40, 10000] (* see A106856 *)

KEYWORD

nonn,easy,new