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 A217709 #13 Apr 23 2013 11:15:47 %S A217709 16,81,256,512,625,2401,6561,14641,19683,28561,83521,130321,279841, %T A217709 390625,707281,923521,1874161,1953125,2825761,3418801,4879681,5764801, %U A217709 7890481,12117361,13845841,20151121,25411681,28398241,33554432,38950081,40353607,47458321 %N A217709 Numbers of the form p^q^r, for p,q,r primes. %C A217709 Subset of A217261. Sequence suggested by _Kevin L. Schwartz_ in a Facebook discussion. %e A217709 a(1) = 2^2^2 = 16; %e A217709 a(2) = 3^2^2 = 81; %e A217709 a(3) = 2^2^3 = 256; %e A217709 a(4) = 2^3^2 = 512; %e A217709 a(5) = 5^2^2 = 625. %Y A217709 Cf. A000040, A000961, A217261. %K A217709 nonn,easy %O A217709 1,1 %A A217709 _Jonathan Vos Post_, Mar 20 2013 %E A217709 More terms from _Alois P. Heinz_, Mar 20 2013