A377139 Numbers that have more cubefree divisors than any smaller number.

1, 2, 4, 6, 12, 30, 36, 60, 180, 420, 900, 1260, 4620, 6300, 13860, 44100, 60060, 69300, 180180, 485100, 900900, 3063060, 6306300, 15315300, 58198140, 107207100, 290990700, 1179278100, 1338557220, 2036934900, 6692786100, 22406283900, 38818159380, 46849502700, 194090796900

Offset: 1

Author

Amiram Eldar, Oct 17 2024

Keywords

• nonn

Comments

First differ from A333931 and A353899 at n = 17.

Indices of records in A073184.

The corresponding record values are 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 27, 36, 48, 54, 72, 81, 96, 108, ... (see the link for more values).

Links

• Amiram Eldar, Table of n, a(n) for n = 1..140
• Amiram Eldar, Table of n, a(n), A073184(a(n)) for n = 1..140

Crossrefs

Subsequence of A004709 and A025487.

Cf. A004709, A073184, A333931, A353899, A377140.

Programs

Mathematica

f[p_, e_] := If[e == 1, 2, 3]; d[1] = 1; d[n_] := Times @@ f @@@ FactorInteger[n]; With[{v = Cases[Import["https://oeis.org/A025487/b025487.txt", "Table"], {, }][[;; , 2]]}, seq = {}; dm = 0; Do[If[(dk = d[v[[k]]]) > dm, dm = dk; AppendTo[seq, v[[k]]]], {k, 1, Length[v]}]; seq]