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 A130230 Primes p == 5 (mod 8) such that the Diophantine equation x^2 - p*y^2 = -4 has a solution in odd integers x, y. 1
 5, 13, 29, 53, 61, 109, 149, 157, 173, 181, 229, 277, 293, 317, 397, 421, 461, 509, 541, 613, 653, 661, 733, 773, 797, 821, 853, 941, 1013, 1021, 1061, 1069, 1093, 1109, 1117, 1181, 1229, 1237, 1277, 1373, 1381, 1429, 1453, 1493, 1549, 1597 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS For the Diophantine equation x^2 - p*y^2 = -4 to have a solution in odd integers x, y we must have p == 5 (mod 8) Calculated using Dario Alpern's quadratic Diophantine solver at http://www.alpertron.com.ar/QUAD.HTM Suggested by a discussion on the Number Theory Mailing List, circa Aug 01 2007. LINKS CROSSREFS Cf. A130229. Sequence in context: A194270 A194700 A220500 * A106931 A078370 A247903 Adjacent sequences:  A130227 A130228 A130229 * A130231 A130232 A130233 KEYWORD nonn AUTHOR Warut Roonguthai, Aug 06 2007 STATUS approved

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Last modified March 26 16:55 EDT 2019. Contains 321510 sequences. (Running on oeis4.)