A146352 - OEIS

A146352

Primes p such that continued fraction of (1 + sqrt(p))/2 has period 7: primes in A146332.

89, 109, 113, 137, 373, 389, 509, 653, 797, 853, 997, 1009, 1493, 1997, 2309, 2621, 2677, 3797, 4973, 7817, 7873, 9829, 9833, 12197, 12269, 12821, 14009, 15773, 16661, 16673, 18253, 18269, 20389, 21557, 24197, 24533, 25037, 25741, 30677, 31973, 33941, 34253, 35977

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OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..2000

MAPLE

A146326 := proc(n) if not issqr(n) then numtheory[cfrac]( (1+sqrt(n))/2, 'periodic', 'quotients') ; nops(%[2]) ; else 0 ; fi; end: isA146352 := proc(n) RETURN(isprime(n) and A146326(n) = 7) ; end: for n from 2 to 13000 do if isA146352(n) then printf("%d, \n", n) ; fi; od: # R. J. Mathar, Sep 06 2009

MATHEMATICA

Select[Range[2*10^4], PrimeQ[#] && Length[ContinuedFraction[(1+Sqrt[#])/2][[2]]] == 7 &] (* Amiram Eldar, Mar 30 2020 *)

CROSSREFS

Cf. A000290, A050950-A050969, A078370, A146326-A146345, A146348-A146360.

Sequence in context: A157764 A032691 A146332 * A050956 A352540 A350724

Adjacent sequences: A146349 A146350 A146351 * A146353 A146354 A146355

KEYWORD

nonn

AUTHOR

Artur Jasinski, Oct 30 2008

EXTENSIONS

607 removed, 797 inserted by R. J. Mathar, Sep 06 2009

More terms from Amiram Eldar, Mar 30 2020

STATUS

approved