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 A146351 Primes p such that continued fraction of (1 + sqrt(p))/2 has period 6: primes in A146331. 1
 19, 59, 107, 131, 499, 659, 1627, 1907, 2251, 2467, 3803, 4139, 4283, 5827, 6779, 9539, 10067, 11491, 12619, 13763, 16987, 18587, 18803, 19507, 22003, 23003, 23819, 24859, 28643, 30859, 37507, 40939, 42083, 42299, 43403, 43867, 44563, 52747, 53507, 55339 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS MAPLE A146326 := proc(n) if not issqr(n) then numtheory[cfrac]( (1+sqrt(n))/2, 'periodic', 'quotients') ; nops(%[2]) ; else 0 ; fi; end: isA146351 := proc(n) RETURN(isprime(n) and A146326(n) = 6) ; end: for n from 2 to 13000 do if isA146351(n) then printf("%d, \n", n) ; fi; od: # R. J. Mathar, Sep 06 2009 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]] == 6, AppendTo[bb, Prime[n]]], {n, 1, Length[aa]}]; bb (* Artur Jasinski *) Select[Prime[Range[10000]], Length[ContinuedFraction[(1+Sqrt[#])/2][[2]]] == 6&] (* Harvey P. Dale, Dec 22 2013 *) CROSSREFS Cf. A000290, A078370, A146326-A146345, A146348-A146360. Sequence in context: A141773 A250024 A031375 * A139920 A182475 A142190 Adjacent sequences:  A146348 A146349 A146350 * A146352 A146353 A146354 KEYWORD nonn AUTHOR Artur Jasinski, Oct 30 2008 EXTENSIONS 797 removed by R. J. Mathar, Sep 06 2009 More terms from Harvey P. Dale, Dec 22 2013 STATUS approved

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Last modified July 19 03:54 EDT 2019. Contains 325144 sequences. (Running on oeis4.)