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 A249052 Odd numbers n without prime factors of the form 4k+3 such that x^2-n*y^2=-1 has no solutions. 1
 205, 221, 305, 377, 505, 545, 689, 725, 745, 793, 905, 1205, 1345, 1405, 1469, 1513, 1517, 1537, 1717, 1885, 1945, 1961, 2005, 2041, 2045, 2105, 2225, 2245, 2329, 2353, 2525, 2533, 2669, 2701, 2845, 2993, 3005, 3205, 3305, 3497, 3505, 3737, 3757, 3805, 3893, 3965, 4069, 4105, 4145, 4205, 4321, 4369 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A positive odd integer n is in this sequence iff its squarefree core A007913(n) belongs to A031398. - Max Alekseyev, Jun 26 2022 LINKS Table of n, a(n) for n=1..52. CROSSREFS Odd terms of A172001. Cf. A031398, A031399, A137351. Sequence in context: A263505 A270605 A072573 * A116177 A191834 A042983 Adjacent sequences: A249049 A249050 A249051 * A249053 A249054 A249055 KEYWORD nonn AUTHOR Joerg Arndt, Apr 09 2008 STATUS approved

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Last modified July 15 19:27 EDT 2024. Contains 374334 sequences. (Running on oeis4.)