A083248 Numbers k such that A045763(k) > A000010(k) > A000005(k).
36, 40, 42, 48, 50, 54, 56, 60, 66, 70, 72, 78, 80, 84, 88, 90, 96, 98, 100, 102, 104, 105, 108, 110, 112, 114, 120, 126, 130, 132, 136, 138, 140, 144, 150, 152, 154, 156, 160, 162, 168, 170, 174, 176, 180, 182, 184, 186, 190, 192, 196, 198, 200, 204, 208, 210
Offset: 1
Keywords
Examples
k = 100 is a term since d(k) = 9, phi(k) = 40, unrelateds(k) = 100 - 9 - 40 + 1 = 52, and 52 > 40 > 9 holds.
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
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Mathematica
Do[r=EulerPhi[n]; d=DivisorSigma[0, n]; u=n-r-d+1; If[Greater[u, r]&&Greater[r, d], Print[n, {d, r, u}]], {n, 1, 1000}] -
PARI
isok(k) = {my(f = factor(k), d = numdiv(f), r = eulerphi(f), u = k - r - d + 1); u > r && r > d;} \\ Amiram Eldar, Feb 08 2025
Comments