A240950 Numbers k such that the continued fraction for sqrt(k) has odd period, omitting those values of k of the form m^2+1.

13, 29, 41, 53, 58, 61, 73, 74, 85, 89, 97, 106, 109, 113, 125, 130, 137, 149, 157, 173, 181, 185, 193, 202, 218, 229, 233, 241, 250, 265, 269, 274, 277, 281, 293, 298, 313, 314, 317, 337, 338, 346, 349, 353, 365, 370, 373, 389, 394, 397, 409, 421, 425, 433

Offset

1,1

Comments

p^2 - n*q^2 = -1 is solvable for integers p and q.

A031396 is the union of this sequence with A002522.

Links

Colin Barker, Table of n, a(n) for n = 1..1000

Example

sqrt(13) = [3;1,1,1,1,6].
sqrt(29) = [5;2,1,1,2,10].

Crossrefs

Cf. A002522, A003814, A031396.

Sequence in context: A141555 A036974 A045472 * A141293 A339956 A352926

Adjacent sequences: A240947 A240948 A240949 * A240951 A240952 A240953

Keyword

nonn

Author

Takao Ito, Aug 04 2014

Extensions

More terms from Colin Barker, Dec 18 2014

Status

approved