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 A363290 #15 Jul 06 2023 13:48:29
%S A363290 2,4,2,4,4,1,0,4,4,9,0,1,5,6,5,3,2,3,6,3,7,2,3,7,4,5,9,7,0,7,9,4,9,7,
%T A363290 0,8,4,1,9,5,8,4,7,7,3,2,7,1,4,7,6,9,4,3,4,2,1,2,6,5,5,9,0,0,1,5,2,7,
%U A363290 9,8,7,0,6,7,0,7,5,4,7,4,6,7,5,0,9,1,3,6,4,4,0,0,7,7,0,3,5
%N A363290 Decimal expansion of the unique x > 0 such that Sum_{n>=0} 1/x^(n!) = 1.
%F A363290 x = 2.424410449015653236372374597079497084...
%e A363290 For x = 2.4244... and remembering that 0! = 1, we have Sum_{n >= 0} 1/x^n! ~ 2 * 1/2.4244 + 1/2.4244^2 + 1/2.4244^6 + 1/2.4244^24 = 1.0000...
%o A363290 (PARI) default(realprecision, 100); solve(x=2,3, sum(n=0,19, x^-n!)-1)
%Y A363290 Cf. A076187.
%K A363290 nonn,cons
%O A363290 1,1
%A A363290 _M. F. Hasler_, May 26 2023