A249052 Odd numbers n without prime factors of the form 4k+3 such that x^2-n*y^2=-1 has no solutions.

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

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