A069148 - OEIS

A069148

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

4, 6, 8, 10, 14, 16, 18, 20, 22, 26, 28, 34, 38, 42, 44, 46, 52, 58, 62, 66, 68, 74, 76, 78, 82, 86, 92, 94, 102, 106, 114, 116, 118, 122, 124, 134, 138, 142, 146, 148, 158, 164, 166, 172, 174, 178, 186, 188, 194, 202, 206, 212, 214, 218, 222, 226, 236, 244, 246

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

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

MATHEMATICA

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

Select[Range[250], !Divisible[#!, #^(DivisorSigma[0, #] - 1)] &] (* Amiram Eldar, Jul 07 2022 *)

PROG

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

CROSSREFS

Complement of A069149.