A102538 Numbers n not of form k(k+2) that have a single '1' in the periodic part of the continued fraction of sqrt(n).

175, 176, 208, 551, 799, 1035, 1247, 1403, 1872, 2856, 2967, 3395, 3496, 3503, 3531, 3731, 3864, 3999, 4136, 4387, 4416, 4512, 4543, 5343, 5368, 5499, 5520, 6099, 6160, 6608, 6751, 7791, 8855, 9048, 10439, 10664, 10904, 11323, 11935, 12208, 13299

Offset: 1

Author

Ralf Stephan, Jan 14 2005

Keywords

• nonn

Comments

Members of A013648 not in A005563.

No prime numbers? - Zak Seidov, Feb 28 2012

Links

• Zak Seidov, Table of n, a(n) for n = 1..1000

Programs

Mathematica

fQ[n_] := Block[{k = Floor[Sqrt[n]]}, If[ k(k + 2) != n && !IntegerQ[ Sqrt[n]], cof = Sort[ ContinuedFraction[ Sqrt[n]] [[2]]]; If[ cof[[1]] == 1 && cof[[2]] != 1, True]]]; Select[ Range[ 13986], fQ[ # ] &] (* Robert G. Wilson v, Jan 25 2005 *)

Extensions

More terms from Robert G. Wilson v, Jan 25 2005