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A031426 Least term in period of continued fraction for sqrt(n) is 2. 1
2, 6, 12, 20, 28, 30, 41, 42, 55, 56, 72, 89, 90, 110, 126, 130, 131, 132, 155, 156, 177, 180, 182, 209, 210, 240, 269, 270, 272, 299, 303, 305, 306, 342, 368, 372, 377, 380, 418, 420, 451, 458, 462, 497, 504, 505, 506, 552, 590, 600, 646, 648 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 (first 1000 from Vincenzo Librandi)

MATHEMATICA

Select[Range[600], !IntegerQ[Sqrt[#]] && Min[ContinuedFraction[Sqrt[#]][[2]]] == 2&] (* Vincenzo Librandi, Feb 06 2012 *)

CROSSREFS

Sequence in context: A028690 A270878 A120344 * A258633 A244362 A175967

Adjacent sequences:  A031423 A031424 A031425 * A031427 A031428 A031429

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified April 22 16:32 EDT 2021. Contains 343177 sequences. (Running on oeis4.)