A377140 Numbers that have more biquadratefree divisors than any smaller number.

1, 2, 4, 6, 12, 24, 36, 60, 120, 180, 360, 840, 1260, 2520, 6300, 7560, 12600, 27720, 69300, 83160, 138600, 360360, 900900, 1081080, 1801800, 5405400, 12612600, 18378360, 30630600, 91891800, 214414200, 349188840, 581981400, 1745944200, 4073869800, 8031343320, 12221609400

Offset: 1

Author

Amiram Eldar, Oct 17 2024

Keywords

• nonn

Comments

First differ from A365681 at n = 22.

Indices of records in A252505.

The corresponding record values are 1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 32, 36, 48, 54, 64, 72, 96, 108, ... (see the link for more values).

Links

• Amiram Eldar, Table of n, a(n) for n = 1..159
• Amiram Eldar, Table of n, a(n), A252505(a(n)) for n = 1..159

Crossrefs

Subsequence of A046100 and A025487.

Cf. A046100, A252505, A365681, A377139.

Programs

Mathematica

f[p_, e_] := Min[e, 3] + 1; 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]