cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A146336 Numbers k such that continued fraction of (1 + sqrt(k))/2 has period 12.

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%I A146336 #18 Mar 31 2020 03:00:56
%S A146336 94,103,124,127,128,158,160,177,190,204,208,209,216,236,239,247,263,
%T A146336 295,296,302,316,332,351,364,376,384,385,415,423,426,432,460,464,479,
%U A146336 492,535,544,585,606,608,609,636,639,666,668,684,696,706,734,736,744,750
%N A146336 Numbers k such that continued fraction of (1 + sqrt(k))/2 has period 12.
%C A146336 For primes in this sequence see A146357.
%H A146336 Amiram Eldar, <a href="/A146336/b146336.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Harvey P. Dale)
%e A146336 a(2) = 103 because continued fraction of (1+sqrt(103))/2 = 15, 1, 1, 2, 1, 6, 20, 6, 1, 2, 1, 1, 9, 1, 1, 2, 1, 6, 20, 6, 1, 2, 1, 1, 9, 1, 1, 2, 1, 6, 20, 6, 1, 2 ... has period (1, 1, 2, 1, 6, 20, 6, 1, 2, 1, 1, 9) length 12.
%t A146336 cf12Q[n_]:=!OddQ[Sqrt[n]]&&Length[ContinuedFraction[(1+Sqrt[n])/2][[2]]]==12; Select[Range[800],cf12Q] (* _Harvey P. Dale_, Oct 15 2011 *)
%Y A146336 Cf. A000290, A078370, A146326-A146345, A146348-A146360.
%K A146336 nonn
%O A146336 1,1
%A A146336 _Artur Jasinski_, Oct 30 2008