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Search: id:A139831
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| A139831 |
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Primes of the form 2x^2+2xy+23y^2. |
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+0
4
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| 2, 23, 47, 83, 107, 167, 227, 263, 347, 383, 443, 467, 503, 563, 587, 647, 683, 743, 827, 863, 887, 947, 983, 1103, 1163, 1187, 1223, 1283, 1307, 1367, 1427, 1487, 1523, 1583, 1607, 1667, 1787, 1823, 1847, 1907, 2003, 2027, 2063, 2087, 2207
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Discriminant=-180. See A139827 for more information.
Except for 2, also primes of the forms 3x^2+20y^2 (A107169) and 8x^2+4xy+23y^2. See A140633. - T. D. Noe (noe(AT)sspectra.com), May 19 2008
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FORMULA
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Except for 2, the primes are congruent to {23, 47} (mod 60).
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MATHEMATICA
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QuadPrimes[2, -2, 23, 10000] (* see A106856 *)
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CROSSREFS
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Sequence in context: A156557 A002428 A105440 this_sequence A049592 A057621 A074809
Adjacent sequences: A139828 A139829 A139830 this_sequence A139832 A139833 A139834
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KEYWORD
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nonn,easy
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AUTHOR
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T. D. Noe (noe(AT)sspectra.com), May 02 2008
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