A074466 a(n) = gcd(n^3, sigma(n^3), phi(n^3)).
1, 1, 1, 1, 1, 24, 1, 1, 1, 20, 1, 8, 1, 8, 15, 1, 1, 3, 1, 4, 1, 8, 1, 24, 1, 4, 1, 16, 1, 1800, 1, 1, 3, 4, 25, 1, 1, 8, 1, 4, 1, 24, 1, 8, 3, 8, 1, 8, 1, 5, 9, 4, 1, 12, 1, 16, 1, 4, 1, 480, 1, 8, 1, 1, 65, 72, 1, 4, 3, 200, 1, 3, 1, 4, 5, 8, 1, 24, 1, 4, 1, 4, 1, 64, 5, 8, 3, 88, 1, 180, 7, 16, 1
Offset: 1
Keywords
Examples
n=10: gcd[1000,2340,400] = 20 = a(10).
Links
- Antti Karttunen, Table of n, a(n) for n = 1..65537
Programs
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Magma
[Gcd(n^3, Gcd(SumOfDivisors(n^3), EulerPhi(n^3))): n in [1..100]]; // Vincenzo Librandi, Sep 20 2018
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Mathematica
Table[Apply[GCD, {w^3, DivisorSigma[1, w^3], EulerPhi[w^3]}], {w, 1, 128}] GCD[#,DivisorSigma[1,#],EulerPhi[#]]&/@(Range[100]^3) (* Harvey P. Dale, Nov 03 2024 *)
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PARI
A074466(n) = gcd([n^3, sigma(n^3), eulerphi(n^3)]); \\ Antti Karttunen, Sep 07 2018
Formula
a(n) = A074389(n^3).