This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A072195 #7 Dec 18 2016 20:49:13 %S A072195 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 A072195 25,26,729,784,1,900,1,1048576,33,34,35,46656,1,38,39,64000,1,1764,1, %U A072195 1936,2025,46,1,5308416,49,2500,51,2704,1,157464,55,175616,57,58,1,216000,1 %N A072195 Replace all prime factors p of n with n/p. %C A072195 For n>1: a(n)=1 iff n is prime. %F A072195 a(n) = n^(A001222(n)-1). %e A072195 a(18) = a(2*3*3) = (18/2)*(18/3)*(18/3) = 9*6*6 = 324. %t A072195 pf[n_]:=Times@@(n/#&/@Flatten[Table[#[[1]],{#[[2]]}]&/@FactorInteger[ n]]); Array[pf,70] (* _Harvey P. Dale_, Dec 11 2013 *) %K A072195 nonn %O A072195 1,4 %A A072195 _Reinhard Zumkeller_, Jul 02 2002