# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a264352 Showing 1-1 of 1 %I A264352 #8 Nov 13 2015 05:13:19 %S A264352 82,146,178,226,274,434,466,514,562,578,626,658,818,914,994,1042,1106, %T A264352 1138,1202,1234,1394,1426,1522,1582,1618,1666,1714,1778,1874,1906, %U A264352 1918,2066,2098,2162,2194,2258,2306,2386,2402,2434,2482,2578,2642 %N A264352 Exceptional even numbers D that do not admit a solution to the Pell equation X^2 - D Y^2 = +2. %C A264352 These are the even numbers D = 2*d with odd d having no prime factors 3 or 5 (mod 8), and do not represent +2 by the indefinite binary quadratic form X^2 - D*Y^2 (with discriminant 4*D > 0). %C A264352 These even D numbers satisfy the necessary condition given in A261246. This condition is not sufficient as the present numbers show. %C A264352 a(n)/2 = d(n) is 7 (mod 8) for n = 24, 31, 48, 55, 57, ... %C A264352 The numbers D which admit solutions to the Pell equation X^2 - D Y^2 = +2 are given by A261246. %C A264352 The exceptional odd D numbers are given in A263010. %Y A264352 Cf. A261246,A263010, A261247, A261248. %K A264352 nonn %O A264352 1,1 %A A264352 _Wolfdieter Lang_, Nov 12 2015 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE