A333931 Recursive highly composite numbers: numbers with a record number of recursive divisors (A282446).

1, 2, 4, 6, 12, 30, 36, 60, 180, 420, 900, 1260, 4620, 6300, 13860, 44100, 55440, 69300, 180180, 485100, 720720, 900900, 2882880, 3063060, 6306300, 12252240, 15315300, 49008960, 58198140, 107207100, 232792560, 290990700, 931170240, 1163962800, 2036934900, 4655851200

Offset

1,2

Comments

The corresponding record values are 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 27, 36, 48, 54, ...

Links

Amiram Eldar, Table of n, a(n) for n = 1..200

Mathematica

recDivNum[1] = 1; recDivNum[n_] := recDivNum[n] = Times @@ (1 + recDivNum/@ (Last /@ FactorInteger[n])); rm = 0; s = {}; Do[r = recDivNum[n]; If[r > rm, rm = r; AppendTo[s, n]], {n, 1, 10^4}]; s

Crossrefs

Subsequence of A025487.

Cf. A282446.

Analogous sequences: A002182 (highly composite), A002110 (unitary), A037992 (infinitary), A293185 (bi-unitary), A309141 (nonunitary), A318278 (exponential).

Sequence in context: A220423 A335068 A372092 * A353899 A308618 A283021

Adjacent sequences: A333928 A333929 A333930 * A333932 A333933 A333934

Keyword

nonn

Author

Amiram Eldar, Apr 10 2020

Status

approved