A091448 Numbers k such that a1 > a2, where [a0,a1,a2,...] is the simple continued fraction of sqrt(k).

19, 28, 29, 52, 53, 54, 67, 70, 85, 86, 88, 103, 106, 107, 108, 124, 125, 126, 127, 129, 149, 151, 153, 172, 173, 174, 175, 176, 178, 179, 199, 201, 202, 204, 206, 207, 229, 232, 233, 234, 236, 237, 259, 261, 262, 263, 265, 267, 268, 292, 293, 294, 295, 296

Offset: 1

Author

Clark Kimberling, Jan 10 2004

Keywords

• nonn

Examples

			sqrt(19) = [4;2,1,3,1,2,8,...], for which a1 = 2 > 1 = a2.
		

Crossrefs

Cf. A000196, A091453.

Programs

Mathematica

Select[Range@300,Quiet[#[[1]]>#[[2]]&[Last@ContinuedFraction[Sqrt@#]]]&] (* Giorgos Kalogeropoulos, Jul 04 2021 *)

PARI

for(k=2,300,my(c=contfrac(sqrt(k)));if(#c>=3&&c[2]>c[3],print1(k,", "))) \\ Hugo Pfoertner, Jul 04 2021