A064621 Values of A005132(n) at which the ratio A005132(n)/n sets a new record.

1, 3, 6, 13, 20, 62, 113, 224, 367, 494, 833, 9169, 131313, 155719, 180118, 280766754, 3454917187, 31685027464, 152431947617, 629621648241

Offset

1,2

Comments

See A064622 for associated values of n.

No other terms < 4 * 10^12. - Jud McCranie, Dec 29 2019

Links

Table of n, a(n) for n=1..20.

Index entries for sequences related to Recamán's sequence

Example

A005132(7)=20, 20/7 = 2.857..., larger than the ratio for any smaller value of n.

Mathematica

Block[{s = Nest[Append[#1, If[And[#3 > 0, FreeQ[#1, #3]], #3, #1[[-1]] + #2]] & @@ {#1, #2, #1[[-1]] - #2} & @@ {#, Length@ #} &, {0}, 200000], t}, t = MapIndexed[#1/First@ #2 &, s]; Rest@ Map[s[[FirstPosition[t, #][[1]] ]] &, Union@ FoldList[Max, t]] ] (* Michael De Vlieger, Dec 29 2019 *)

Crossrefs

Cf. A005132, A064622.

Sequence in context: A361273 A318228 A064290 * A330588 A194279 A293822

Adjacent sequences: A064618 A064619 A064620 * A064622 A064623 A064624

Keyword

more,nonn

Author

Jud McCranie, Sep 26 2001

Extensions

Offset changed, a(19)-a(20) from Jud McCranie, Dec 28 2019

Status

approved