Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #18 Mar 05 2023 11:36:16
%S 421,757,1021,1097,1117,1301,1553,1973,2069,2237,2273,2789,2861,3373,
%T 3461,3517,3877,3917,4133,4397,4481,5521,5573,5717,6221,6317,6637,
%U 6997,7253,7517,8741,9049,9173,9437,10181,10949,11597,11789,12497,15473,15797,16141,18353
%N Primes p such that continued fraction of (1 + sqrt(p))/2 has period 13: primes in A333640.
%H Amiram Eldar, <a href="/A146358/b146358.txt">Table of n, a(n) for n = 1..2000</a>
%t Select[Range[2*10^4], PrimeQ[#] && Length[ContinuedFraction[(1+Sqrt[#])/2][[2]]] == 13 &] (* _Amiram Eldar_, Mar 30 2020 *)
%t Select[Prime[Range[2500]],Length[ContinuedFraction[(1+Sqrt[#])/2][[2]]]==13&] (* _Harvey P. Dale_, Mar 05 2023 *)
%Y Cf. A000290, A050950-A050969, A078370, A146326-A146345, A333640, A146348-A146360.
%K nonn
%O 1,1
%A _Artur Jasinski_, Oct 30 2008
%E Definition corrected, 3 terms added. - _R. J. Mathar_, Nov 08 2008
%E More terms from _Amiram Eldar_, Mar 30 2020