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.

A064622 Values of n at which the ratio A005132(n)/n sets a new record.

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%I A064622 #37 Dec 30 2019 12:13:33
%S A064622 1,2,3,6,7,19,34,67,102,115,190,2066,24381,24398,24399,36130540,
%T A064622 409493529,3744514071,17951662018,71184216405
%N A064622 Values of n at which the ratio A005132(n)/n sets a new record.
%C A064622 See A064621 for associated values of A005132.
%C A064622 No other terms < 4.61 * 10^11. - _Jud McCranie_, Dec 29 2019
%H A064622 <a href="/index/Rea#Recaman">Index entries for sequences related to Recamán's sequence</a>
%e A064622 A005132(7)=20, 20/7 = 2.857..., larger than the ratio for any smaller value of n. So 7 is in the sequence.
%t A064622 Block[{s = Nest[Append[#1, If[And[#3 > 0, FreeQ[#1, #3]], #3, #1[[-1]] + #2]] & @@ {#1, #2, #1[[-1]] - #2} & @@ {#, Length@ #} &, {0}, 10^5], t}, t = MapIndexed[#1/First@ #2 &, s]; -1 + Rest@ Map[FirstPosition[t, #][[1]] &, Union@ FoldList[Max, t]] ] (* _Michael De Vlieger_, Dec 29 2019 *)
%Y A064622 Cf. A005132, A064621.
%K A064622 nonn,more
%O A064622 1,2
%A A064622 _Jud McCranie_, Sep 26 2001
%E A064622 Two more terms from _John W. Layman_ and _N. J. A. Sloane_, Oct 12 2001
%E A064622 Offset changed, a(19)-a(20) from _Jud McCranie_, Dec 28 2019