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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A146350 Primes p such that continued fraction of (1+Sqrt[p])/2 has period 5 : primes in A146330. 1
41, 149, 157, 181, 269, 397, 761, 941, 1013, 2081, 2153, 2477, 2693, 3181, 3221, 3533, 4253, 4409, 5273, 5297, 5741, 6949, 8069, 8501, 8597, 9293, 10301, 10357, 10957, 11321, 12281, 12589, 13313, 17477, 19477, 19949, 20369, 21433, 22397, 23957, 26309 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A050954 is subset of this sequence.

LINKS

Table of n, a(n) for n=1..41.

MATHEMATICA

$MaxExtraPrecision = 4000; s = 10; aa = {}; Do[k = ContinuedFraction[(1 + Sqrt[Prime[n]])/2, 3000]; m = 1; While[k[[s]] != k[[s + m]] || k[[s + m]] != k[[s + 2 m]] || k[[s + 2 m]] != k[[s + 3 m]] || k[[s + 3 m]] != k[[s + 4 m]] || k[[s + 4 m]] != k[[s + 5 m]], m++ ]; s = s + 1; While[k[[s]] != k[[s + m]] || k[[s + m]] != k[[s + 2 m]] || k[[s + 2 m]] != k[[s + 3 m]] || k[[s + 3 m]] != k[[s + 4 m]] || k[[s + 4 m]] != k[[s + 5 m]], m++ ]; s = s + 1; While[k[[s]] != k[[s + m]] || k[[s + m]] != k[[s + 2 m]] || k[[s + 2 m]] != k[[s + 3 m]] || k[[s + 3 m]] != k[[s + 4 m]] || k[[s + 4 m]] != k[[s + 5 m]]; AppendTo[aa, m]], {n, 1, 1495}]; bb = {}; Do[If[aa[[n]] == 5, AppendTo[bb, Prime[n]]], {n, 1, Length[aa]}]; bb (*Artur Jasinski*)

Select[Prime[Range[2000]], Length[ContinuedFraction[(1+Sqrt[#])/2][[2]]] == 5&] (* Harvey P. Dale, Aug 13 2016 *)

CROSSREFS

A000290, A078370, A146326-A146345, A146348-A146360.

Sequence in context: A217087 A303910 A146330 * A050954 A192821 A141957

Adjacent sequences:  A146347 A146348 A146349 * A146351 A146352 A146353

KEYWORD

nonn

AUTHOR

Artur Jasinski, Oct 30 2008

EXTENSIONS

More terms from Harvey P. Dale, Aug 13 2016

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 August 18 15:00 EDT 2019. Contains 326106 sequences. (Running on oeis4.)