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A363330
Numbers with a record number of divisors that are both coreful and infinitary.
1
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).
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
KEYWORD
nonn
AUTHOR
Amiram Eldar, May 28 2023
STATUS
approved