A159973 - OEIS

%I #6 Aug 31 2023 17:57:49

%S 3,4,5,6,7,10,11,13,14,15,16,17,19,20,21,22,23,25,26,27,28,29,30,31,

%T 32,33,34,35,37,38,39,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,57,

%U 58,59,61,62,63,64,65,66,67,68,69,70,71,73,74,75,76,77,78,79,81,82,83,85

%N Non-refactorable numbers: number of divisors of n does not divide n.

%t Select[Range[100],Mod[#,DivisorSigma[0,#]]!=0&] (* _Harvey P. Dale_, Aug 31 2023 *)

%o (Magma) [ n: n in [1..85] | n mod #Divisors(n) ne 0 ];

%Y Complement of A033950.

%K nonn

%O 1,1

%A _Jaroslav Krizek_, Apr 28 2009

%E Edited and extended by _Klaus Brockhaus_, Apr 29 2009