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 A091324 #3 Mar 30 2012 16:49:51
%S A091324 1,3,175,11012415,11878335717996660991,
%T A091324 932357239278482603486754898815444262218545775615,
%U A091324 25020804906535555378545307822902185893828140712948517836661141440629855580651950069203769685588364042197142274707455
%N A091324 (2^n)^(2^n)-(2^n-1)^(2^n).
%C A091324 Number of maps from {0,1}^n to itself with at least one root.
%D A091324 F. Robert, Discrete Iterations, Springer-Verlag, 1986, p. 167.
%Y A091324 Cf. A057156, A092258.
%K A091324 nonn
%O A091324 0,2
%A A091324 _N. J. A. Sloane_, Feb 19 2004