A326712 Numbers with a record sum of divisors, weighted by divisor multiplicity (A168512).
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
Keywords
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.
Links
- Amiram Eldar, Table of n, a(n) for n = 1..600
Programs
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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 *)
Comments