A069148 - OEIS

%I #16 Jul 07 2022 08:11:58

%S 4,6,8,10,14,16,18,20,22,26,28,34,38,42,44,46,52,58,62,66,68,74,76,78,

%T 82,86,92,94,102,106,114,116,118,122,124,134,138,142,146,148,158,164,

%U 166,172,174,178,186,188,194,202,206,212,214,218,222,226,236,244,246

%N Numbers k such that k*k!/A062758(k) is not an integer where A062758(k) is the product of squares of divisors of k.

%H Amiram Eldar, <a href="/A069148/b069148.txt">Table of n, a(n) for n = 1..10000</a>

%t Rest[Position[Table[(n*n!)/(Times@@Divisors[n])^2,{n,250}],_?(!IntegerQ[ #]&)]//Flatten] (* _Harvey P. Dale_, Apr 24 2019 *)

%t Select[Range[250], !Divisible[#!, #^(DivisorSigma[0, #] - 1)] &] (* _Amiram Eldar_, Jul 07 2022 *)

%o (PARI) for(n=1,320,if((n*(n!))%(n^numdiv(n))>0,print1(n,",")))

%Y Complement of A069149.

%Y Cf. A001563 (n*n!), A062758.

%K easy,nonn

%O 1,1

%A _Benoit Cloitre_, Apr 08 2002