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 A346190 #8 Jan 14 2023 13:27:38
%S A346190 5,0,7,8,1,2,5,0,0,4,6,5,6,6,1,2,8,7,3,0,7,7,3,9,2,5,7,8,1,2,5,0,0,0,
%T A346190 0,0,0,0,5,8,7,7,4,7,1,7,5,4,1,1,1,4,3,7,5,3,9,8,4,3,6,8,2,6,8,6,1,1,
%U A346190 1,2,2,8,3,8,9,0,9,3,3,2,7,7,8,3,8,6,0,4,3,7,6,0,7,5,4,3,7,5,8,5
%N A346190 Decimal expansion of Sum_{k>=0} 1/(2^(2^(2*k+1)) - 1).
%C A346190 This constant is transcendental (Schwarz, 1967).
%H A346190 Wolfgang Schwarz, <a href="https://www.jstor.org/stable/24489854">Remarks on the irrationality and transcendence of certain series</a>, Mathematica Scandinavica, Vol. 20, No. 2 (1967), pp. 269-274; <a href="https://www.mscand.dk/article/download/10836/8857">alternative link</a>.
%H A346190 <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>
%F A346190 Equals A076214 - A346191.
%e A346190 0.50781250046566128730773925781250000000587747175411...
%t A346190 RealDigits[Sum[1/(2^(2^(2*n + 1) - 1)), {n, 0, 10}], 10, 100][[1]]
%Y A346190 Cf. A048649, A076214, A346191, A346192.
%K A346190 nonn,cons
%O A346190 0,1
%A A346190 _Amiram Eldar_, Jul 09 2021