A363330 Numbers with a record number of divisors that are both coreful and infinitary.

1, 8, 128, 216, 3456, 27000, 279936, 432000, 9261000, 34992000, 148176000, 8957952000, 12002256000, 197222256000, 3072577536000, 7501410000000, 15975002736000, 433297296432000, 1920360960000000, 4089600700416000, 9984376710000000, 35097081010992000, 2128789617370416000

Offset

1,2

Comments

Indices of records in A363329.

The corresponding record values are 1, 3, 7, 9, 21, 27, 49, 63, 81, 147, 189, 315, ... (see the link for more values).

Links

Amiram Eldar, Table of n, a(n) for n = 1..64

Amiram Eldar, Table of n, a(n), A363329(a(n)) for n = 1..64

Mathematica

f[p_, e_] := 2^DigitCount[e, 2, 1] - 1; d[1] = 1; d[n_] := Times @@ f @@@ FactorInteger[n];
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

Cf. A363329.

Subsequence of A025487.

Similar sequences: A005934, A037992.

Sequence in context: A034239 A171755 A338808 * A233089 A204194 A093586

Adjacent sequences: A363327 A363328 A363329 * A363331 A363332 A363333

Keyword

nonn

Author

Amiram Eldar, May 28 2023

Status

approved