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A309141 Nonunitary highly composite numbers: numbers with a record number of nonunitary divisors. 11
1, 4, 8, 16, 24, 36, 48, 72, 144, 216, 288, 360, 576, 720, 1080, 1440, 2160, 2880, 3600, 4320, 5040, 7200, 7560, 10080, 15120, 20160, 25200, 30240, 45360, 50400, 60480, 75600, 100800, 110880, 151200, 221760, 277200, 302400, 332640, 453600, 498960, 554400, 665280 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Numbers k with A048105(k) > A048105(j) for all j < k.
The corresponding values of records are 0, 1, 2, 3, 4, 5, 6, 8, 11, 12, 14, 16, 17, 22, 24, 28, 32, 34, 37, 40, 44, 46, 48, 56, 64, 68, 74, 80, 84, 92, 96, ... (see the link for more values)
LINKS
MATHEMATICA
f[n_] := DivisorSigma[0, n] - 2^PrimeNu[n]; fm=-1; s={}; Do[f1 = f[n]; If[f1 > fm, fm = f1; AppendTo[s, n]], {n, 1, 10^5}]; s
CROSSREFS
Cf. A048105, A002182 (highly composite), A002110 (unitary), A037992 (infinitary), A293185 (bi-unitary), A318278 (exponential).
Sequence in context: A355392 A290498 A137932 * A329882 A309181 A140466
KEYWORD
nonn
AUTHOR
Amiram Eldar, Jul 14 2019
STATUS
approved

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Last modified March 29 04:59 EDT 2024. Contains 371264 sequences. (Running on oeis4.)