A291928 Positions of records in A218320.

1, 4, 8, 12, 16, 24, 36, 48, 72, 96, 120, 144, 216, 240, 288, 360, 480, 576, 720, 1080, 1440, 2160, 2520, 2880, 3360, 3600, 4320, 5040, 7200, 7560, 8640, 10080, 15120, 20160, 25200, 30240, 40320, 45360, 50400, 60480, 75600, 90720, 100800, 110880, 120960

Offset: 1

Author

Michael De Vlieger, Sep 06 2017

Keywords

• nonn

Comments

Distinct from A033833; first term not in A033833 is a(24) = 2520. There appear to be increasingly many terms a(n) not in A033833 as n increases.

A291834(13) = 192 is the smallest term not in a(n).

Subsequence of A025487.

Links

• David A. Corneth, Table of n, a(n) for n = 1..160

Crossrefs

Cf. A002182, A007416, A025487, A033833, A218320.

Programs

Mathematica

f[n_, i_, t_] := f[n, i, t] = If[n == 1, 1, If[t == 1, Boole[n <= i], Sum[f[n/d, d, t - 1], {d, Select[Divisors@ n, # <= i &]}]]]; With[{s = Array[f[#, #, 4] &, 10^5]}, Map[FirstPosition[s, #][[1]] &, Union@ FoldList[Max, s]]] (* Michael De Vlieger, Sep 06 2017, after Alois P. Heinz at A218320 *)