login
Replace all prime factors p of n with n/p.
2

%I #7 Dec 18 2016 20:49:13

%S 1,1,1,4,1,6,1,64,9,10,1,144,1,14,15,4096,1,324,1,400,21,22,1,13824,

%T 25,26,729,784,1,900,1,1048576,33,34,35,46656,1,38,39,64000,1,1764,1,

%U 1936,2025,46,1,5308416,49,2500,51,2704,1,157464,55,175616,57,58,1,216000,1

%N Replace all prime factors p of n with n/p.

%C For n>1: a(n)=1 iff n is prime.

%F a(n) = n^(A001222(n)-1).

%e a(18) = a(2*3*3) = (18/2)*(18/3)*(18/3) = 9*6*6 = 324.

%t pf[n_]:=Times@@(n/#&/@Flatten[Table[#[[1]],{#[[2]]}]&/@FactorInteger[ n]]); Array[pf,70] (* _Harvey P. Dale_, Dec 11 2013 *)

%K nonn

%O 1,4

%A _Reinhard Zumkeller_, Jul 02 2002