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.

A326712 Numbers with a record sum of divisors, weighted by divisor multiplicity (A168512).

Original entry on oeis.org

1, 2, 3, 4, 6, 8, 12, 16, 18, 20, 24, 30, 32, 36, 48, 60, 72, 84, 90, 96, 108, 120, 144, 168, 180, 210, 216, 240, 288, 300, 324, 336, 360, 420, 480, 504, 540, 576, 600, 660, 672, 720, 840, 900, 960, 1008, 1080, 1200, 1260, 1440, 1560, 1620, 1680, 1800, 1920, 1980, 2016
Offset: 1

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Author

Amiram Eldar, Oct 18 2019

Keywords

Comments

The corresponding record values are 1, 3, 4, 9, 12, 19, 30, 41, 42, 44, 64, 72, 75, 102, 134, 170, 208, 226, 237, 264, 294, ...

Examples

			The first values of A168512(n) for n=1..8 are {1, 3, 4, 9, 6, 12, 8, 19}. The record values are 1, 3, 4, 9, 12, 19 for 1, 2, 3, 4, 6, 8. Therefore this sequence begins with 1, 2, 3, 4, 6, 8.
		

Crossrefs

Programs

  • Mathematica
    s[n_] := 1 + DivisorSum[n, #*IntegerExponent[n, #] &, # > 1 &]; seq = {}; sm = 0; Do[s1 = s[n]; If[s1 > sm, sm = s1; AppendTo[seq, n]], {n, 1, 100000}]; seq (* after Michael De Vlieger at A168512 *)