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 A260229 #23 Aug 07 2015 05:14:47
%S A260229 2,7,403,26489122129,
%T A260229 13041808783936322797338790280986488113446079415755132
%N A260229 a(n) = floor(e^(n!)).
%C A260229 The exponential growth in the number of permutations of n elements.
%C A260229 Next term is too big to be included.
%F A260229 a(n) = A000149(A000142(n)).
%F A260229 a(n) = floor(sqrt(e^A052849(n) - e^A000142(n) + sqrt(e^A052849(n) - e^A000142(n) + sqrt(e^A052849(n) - e^A000142(n) + ...)))).
%e A260229 a(1) = floor(e^(1!)) = floor(e) = 2.
%t A260229 Table[Floor[E^n!], {n, 1, 7}]
%o A260229 (PARI) default(realprecision, 100); vector(5, n, floor(exp(n!))) \\ _Michel Marcus_, Aug 06 2015
%Y A260229 Cf. A000149, A000142.
%Y A260229 Cf. A050923, A100731.
%K A260229 nonn
%O A260229 1,1
%A A260229 _Ilya Gutkovskiy_, Jul 20 2015