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 A050764 #13 Aug 24 2019 12:09:33
%S A050764 1,4,27,256,3125,823543,387420489,437893890380859375,
%T A050764 39346408075296537575424
%N A050764 Numbers of form k^k (for values of k see A050763) containing no pair of consecutive equal digits (probably finite).
%t A050764 Select[Table[k^k,{k,20}],FreeQ[Differences[IntegerDigits[#]],0]&] (* _Harvey P. Dale_, Aug 23 2019 *)
%Y A050764 Cf. A043096, A000312, A050763, A049329.
%K A050764 nonn,base
%O A050764 1,2
%A A050764 _Patrick De Geest_, Sep 15 1999
%E A050764 Since this is a list, it has offset 1 and does not contain any repeated terms. - _N. J. A. Sloane_, Aug 24 2019