A054011 n is not divisible by the number of its proper divisors.
8, 9, 10, 12, 14, 18, 22, 24, 25, 26, 28, 30, 32, 34, 35, 36, 38, 40, 44, 46, 48, 49, 52, 54, 55, 58, 60, 62, 63, 64, 65, 66, 68, 72, 74, 76, 77, 78, 80, 81, 82, 84, 85, 86, 88, 90, 91, 92, 94, 95, 96, 98, 99, 100, 102, 104, 106, 108, 110, 112, 114, 115, 116, 117, 118, 119
Offset: 1
Keywords
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000
Programs
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Maple
with(numtheory): [seq(`if`(i mod (tau(i)-1) <> 0,i,print( )), i=2..190)];
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Mathematica
Select[Range[2, 120], ! Divisible[#, DivisorSigma[0, #] - 1] &] (* Amiram Eldar, Aug 28 2019 *)