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

Author

Asher Auel, Jan 17 2000

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000005, A032741, A054009, A054012.

Programs

Maple

with(numtheory): [seq(`if`(i mod (tau(i)-1) <> 0,i,print( )), i=2..190)];

Mathematica

Select[Range[2, 120], ! Divisible[#, DivisorSigma[0, #] - 1] &] (* Amiram Eldar, Aug 28 2019 *)