# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a140018 Showing 1-1 of 1 %I A140018 #18 Sep 08 2022 08:45:34 %S A140018 7,223,307,643,787,1123,1567,1627,1783,1867,1987,2203,2803,3307,3463, %T A140018 3547,3583,3967,4483,4903,4987,5323,5647,5683,6247,6823,7027,7243, %U A140018 7507,7867,8263,8287,8923,9007,9043,9547,10303,10723,11863,12043 %N A140018 Primes of the form 7x^2+195y^2. %C A140018 Discriminant=-5460. See A139827 for more information. %H A140018 Vincenzo Librandi and Ray Chandler, Table of n, a(n) for n = 1..10000 [First 1000 terms from Vincenzo Librandi] %H A140018 N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references) %F A140018 The primes are congruent to {7, 187, 223, 307, 643, 787, 943, 1123, 1207, 1363, 1567, 1627, 1783, 1867, 1903, 1987, 2047, 2203, 2407, 2803, 2827, 3127, 3307, 3463, 3547, 3583, 3967, 4063, 4087, 4387, 4483, 4843, 4903, 4987, 5143, 5263, 5323} (mod 5460). %t A140018 QuadPrimes2[7, 0, 195, 10000] (* see A106856 *) %t A140018 With[{nn=50},Take[Select[Union[7First[#]^2+195Last[#]^2&/@Tuples[ Range[ 0,nn],2]],PrimeQ],nn]] (* _Harvey P. Dale_, Aug 29 2014 *) %o A140018 (Magma) [ p: p in PrimesUpTo(13000) | p mod 5460 in {7, 187, 223, 307, 643, 787, 943, 1123, 1207, 1363, 1567, 1627, 1783, 1867, 1903, 1987, 2047, 2203, 2407, 2803, 2827, 3127, 3307, 3463, 3547, 3583, 3967, 4063, 4087, 4387, 4483, 4843, 4903, 4987, 5143, 5263, 5323} ]; // _Vincenzo Librandi_, Aug 05 2012 %K A140018 nonn,easy %O A140018 1,1 %A A140018 _T. D. Noe_, May 02 2008 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE