A119500 Numbers n such that A114717(n) sets a new record.

1, 6, 12, 24, 30, 60, 120, 180, 240, 360, 420, 720, 840, 1260, 1680, 2520, 4620, 5040, 7560, 9240

Offset: 1

Author

Antti Karttunen, May 26 2006

Keywords

• nonn

Comments

This sequence gives yet another list of "increasingly compound" numbers.

Crossrefs

Cf. A119499, A018894. Subset of A119840.

Programs

Mathematica

b[s_] := b[s] = If[Length[s] < 2, 1, Sum[If[Length[Select[s, Mod[#, x] == 0 &]] == 1, b[Complement[s, {x}]], 0], {x, s}]]; a[n_] := a[n] = Module[{l, m}, l = Sort[FactorInteger[n], #1[[2]] > #2[[2]] &]; m = Product[Prime[i ]^l[[i]][[2]], {i, 1, Length[l]}]; b[Divisors[m] // Rest // Most]]; A119500 = Reap[For[record = 0; k = 1, k < 10^4, k++, ak = a[k]; If[ak > record, record = ak; Print[k, " ", ak]; Sow[k]]]][[2, 1]] (* Jean-François Alcover, Mar 03 2016, after Alois P. Heinz *)

Extensions

a(11)-a(17) from Alois P. Heinz, Aug 06 2012

a(18)-a(20) from Alois P. Heinz, Feb 25 2016