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A054011 n is not divisible by the number of its proper divisors. 2

%I #9 Oct 27 2023 22:00:46

%S 8,9,10,12,14,18,22,24,25,26,28,30,32,34,35,36,38,40,44,46,48,49,52,

%T 54,55,58,60,62,63,64,65,66,68,72,74,76,77,78,80,81,82,84,85,86,88,90,

%U 91,92,94,95,96,98,99,100,102,104,106,108,110,112,114,115,116,117,118,119

%N n is not divisible by the number of its proper divisors.

%H Amiram Eldar, <a href="/A054011/b054011.txt">Table of n, a(n) for n = 1..10000</a>

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

%t Select[Range[2, 120], ! Divisible[#, DivisorSigma[0, #] - 1] &] (* _Amiram Eldar_, Aug 28 2019 *)

%Y Cf. A000005, A032741, A054009, A054012.

%K nonn

%O 1,1

%A _Asher Auel_, Jan 17 2000

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Last modified April 19 21:09 EDT 2024. Contains 371798 sequences. (Running on oeis4.)