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 A111260 #8 Jul 31 2015 21:41:19
%S A111260 1,4,16,27,256,729,65536,2985984,4194304,9765625,134217728,387420489,
%T A111260 2176782336,24794911296,30517578125,104857600000,678223072849,
%U A111260 2641807540224,7625597484987,17592186044416,281474976710656
%N A111260 Numbers of the form (m^n)/(n^m) with m > 0 and n>1.
%e A111260 The 4th element is a=27 with m = 3 and n = 9 because 3^9/9^3 = 27.
%p A111260 a:=proc(N) local a, m,n; for m from 1 to N do for n from 2 to N do a:=(m^n)/(n^m); if(floor(a)=a)then print(a) fi; od; od; end: # convert into set # sort set
%t A111260 Take[ Select[ Union@Flatten@Table[(m^n)/(n^m), {m, 35}, {n, 2, 35}], IntegerQ[ # ] &], 21] (* _Robert G. Wilson v_, Nov 17 2005 *)
%Y A111260 Cf. A072651, A072652, A072653.
%K A111260 nonn
%O A111260 1,2
%A A111260 _Giorgio Balzarotti_ and _Paolo P. Lava_, Nov 12 2005