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A081234 Let p = n-th prime, take smallest solution (x,y) to the Pellian equation x^2 - p*y^2 = 1 with x and y >= 1; sequence gives value of y. 4
2, 1, 4, 3, 3, 180, 8, 39, 5, 1820, 273, 12, 320, 531, 7, 9100, 69, 226153980, 5967, 413, 267000, 9, 9, 53000, 6377352, 20, 22419, 93, 15140424455100, 113296, 419775, 927, 519712, 6578829, 2113761020, 140634693, 3726964292220, 5019135, 13, 190060 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..40.

N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)

MATHEMATICA

PellSolve[(m_Integer)?Positive] := Module[{cf, n, s}, cf = ContinuedFraction[ Sqrt[m]]; n = Length[Last[cf]]; If[OddQ[n], n = 2*n]; s = FromContinuedFraction[ ContinuedFraction[ Sqrt[m], n]]; {Numerator[s], Denominator[s]}]; Table[ PellSolve[ Prime[n]][[2]], {n, 40}] (* Robert G. Wilson v, Jul 22 2005 *)

CROSSREFS

Values of x are in A081233. Equals A002349(p). Cf. A082393.

Sequence in context: A117235 A159573 A102916 * A105239 A261366 A283166

Adjacent sequences:  A081231 A081232 A081233 * A081235 A081236 A081237

KEYWORD

easy,nonn

AUTHOR

N. J. A. Sloane, Apr 18 2003

EXTENSIONS

More terms (a(8) - a(40)) from Robert G. Wilson v, Jul 22 2005

STATUS

approved

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Last modified November 19 07:02 EST 2017. Contains 294915 sequences.