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.

A089642 Numbers m such that there is a single k, 1 <= k <= m, such that the number of elements in the continued fraction for m/k is maximum.

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%I A089642 #15 Jun 14 2022 02:27:02
%S A089642 1,3,4,5,8,12,13,15,21,30,34,39,40,42,48,55,56,65,72,74,80,89,102,110,
%T A089642 130,144,168,170,176,180,185,193,194,208,233,272,275,288,297,299,312,
%U A089642 336,340,377,400,445,456,468,517,546,550,610,638,699,715,720,754,777
%N A089642 Numbers m such that there is a single k, 1 <= k <= m, such that the number of elements in the continued fraction for m/k is maximum.
%C A089642 Except for 2, all Fibonacci numbers are in the sequence.
%H A089642 Amiram Eldar, <a href="/A089642/b089642.txt">Table of n, a(n) for n = 1..250</a>
%t A089642 q[n_] := Count[len = Length[ContinuedFraction[n/#]] & /@ Range[n], Max[len]] == 1; Select[Range[1000], q] (* _Amiram Eldar_, Jun 14 2022 *)
%o A089642 (PARI) for(n=1,330,if(sum(s=1,n,if(length(contfrac(n/s))-vecmax(vector(n,i,length(contfrac(n/i)))),0,1))==1,print1(n,",")))
%Y A089642 Cf. A000045, A084242.
%K A089642 nonn
%O A089642 1,2
%A A089642 _Benoit Cloitre_, Jan 01 2004
%E A089642 More terms from _Jinyuan Wang_, Apr 06 2020