cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A326677 Numbers with a record number of divisors, counted with multiplicity (A169594).

Original entry on oeis.org

1, 2, 4, 8, 12, 16, 24, 32, 36, 48, 64, 72, 96, 120, 144, 240, 288, 360, 432, 576, 720, 1080, 1260, 1440, 2160, 2520, 2880, 3600, 5040, 7200, 7560, 8640, 10080, 14400, 15120, 20160, 25200, 30240, 40320, 45360, 50400, 55440, 75600, 100800, 110880, 151200, 166320
Offset: 1

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Author

Amiram Eldar, Oct 18 2019

Keywords

Comments

The corresponding record values are 1, 2, 4, 6, 7, 9, 10, 11, 12, 14, 15, 16, 17, 18, 22, 24, 26, 28, 29, ...
Since the value of A169594(k) depends only on the prime signature of k, this sequence is a subsequence of A025487.

Examples

			The first values of A169594(n) for n=1..8 are {1, 2, 2, 4, 2, 4, 2, 6}. The record values are 1, 2, 4, 6, for 1, 2, 4, 8. Therefore this sequence begins with 1, 2, 4, 8.
		

Crossrefs

Programs

  • Mathematica
    d[n_]:=1 + DivisorSum[n, IntegerExponent[n, #] &, # > 1 &]; s={}; dm = 0; Do[d1 = d[n]; If[d1 > dm, dm = d1; AppendTo[s, n]], {n, 1, 10000}]; s (* after Michael De Vlieger at A169594 *)