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%I #18 Sep 08 2022 08:46:24
%S 1,5,6,7,8,10,11,12,13,14,15,17,18,19,20,21,22,23,24,26,27,28,29,30,
%T 31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,
%U 54,55,56,57,58,59,60,61,62,63,65,66,67,68,69,70,71,72,73
%N Numbers m such that m! / sigma(m) is an integer.
%C Complement of A325436.
%C Corresponding integers are 1, 20, 60, 630, 2688, 201600, 3326400, 17107200, ...
%C Equals A163162 without number 3.
%e 6 is in the sequence because 6! / sigma(6) = 720 / 12 = 60 (integer).
%t Select[Range[80],IntegerQ[#!/DivisorSigma[1,#]]&] (* _Harvey P. Dale_, Jul 20 2022 *)
%o (Magma) [n: n in [1..1000] | IsIntegral(Factorial(n)/&+[d: d in Divisors(n)])]
%o (PARI) isok(n) = ((n! % sigma(n)) == 0); \\ _Michel Marcus_, Apr 26 2019
%Y Cf. A000142, A000203, A053182, A163162, A325436.
%K nonn
%O 1,2
%A _Jaroslav Krizek_, Apr 26 2019
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