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

1,1

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

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 *)

Crossrefs

Sequence in context: A187425 A186218 A245035 * A045145 A351720 A015806

Adjacent sequences: A102535 A102536 A102537 * A102539 A102540 A102541

Keyword

nonn

Author

Ralf Stephan, Jan 14 2005

Extensions

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

Status

approved