login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A033316 Value of D for incrementally largest values of minimal x satisfying Pell equation x^2-Dy^2=1. 5
1, 2, 5, 10, 13, 29, 46, 53, 61, 109, 181, 277, 397, 409, 421, 541, 661, 1021, 1069, 1381, 1549, 1621, 2389, 3061, 3469, 4621, 4789, 4909, 5581, 6301, 6829, 8269, 8941, 9949, 12541, 13381, 16069, 17341, 24049, 24229, 25309, 29269, 30781, 32341, 36061 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Equally, value of D for incrementally largest values of minimal y satisfying Pell equation x^2-Dy^2=1.

Values of n where A002349 (or A002350) sets a new record.

LINKS

Ray Chandler, Table of n, a(n) for n = 1..93

Eric Weisstein's World of Mathematics, Pell Equation.

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]}]; f[n_] := If[ !IntegerQ[ Sqrt[n]], PellSolve[n][[1]], 1]; a = b = -1; t = {}; Do[b = f[n]; If[b > a, t = Append[t, n]; a = b], {n, 1, 40500}]; t

CROSSREFS

Cf. A000037, A033313, A033314, A033315, A002349, A002350.

Sequence in context: A185647 A064392 A018296 * A099194 A140411 A053353

Adjacent sequences:  A033313 A033314 A033315 * A033317 A033318 A033319

KEYWORD

nonn

AUTHOR

Eric W. Weisstein

EXTENSIONS

More terms from Robert G. Wilson v, Apr 15 2003

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 17 13:57 EDT 2019. Contains 328113 sequences. (Running on oeis4.)