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

1,2

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

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]

Crossrefs

Subsequence of A004709 and A025487.

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

Sequence in context: A372092 A333931 A353899 * A308618 A283021 A309039

Adjacent sequences: A377136 A377137 A377138 * A377140 A377141 A377142

Keyword

nonn

Author

Amiram Eldar, Oct 17 2024

Status

approved