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 A380741 #34 Feb 10 2025 04:41:04
%S A380741 1,8,2,8,1,2,5,4,1,7,2,3,2,5,1,3,4,2,7,7,3,4,3,7,5,0,0,0,0,0,0,0,0,0,
%T A380741 0,0,8,2,7,5,4,8,0,2,2,9,7,8,8,9,0,4,0,5,6,0,9,9,9,0,5,2,2,2,0,4,4,6,
%U A380741 0,9,5,7,1,8,4,3,4,0,5,5,1,9,6,7,5,4,9,6,1,5,1,4,2,1,6,1,2,0,1,2,2,0,0,0,5
%N A380741 Decimal expansion of Sum_{k>=1} prime(k)/2^(k!).
%C A380741 Each prime can be recovered from this constant r by prime(k) = floor(r*2^(k!) - floor(r*2^((k-1)!)))*2^((k-1)*(k-1)!) when the binary positions 2^(k!) are far enough apart, which means k>=3.
%C A380741 Is this constant transcendental?
%e A380741 1.828125417232513427734375...
%o A380741 (PARI) suminf(k=1, prime(k)/2^(k!)) \\ _Michel Marcus_, Feb 09 2025
%Y A380741 Cf. A339764.
%K A380741 nonn,cons,easy
%O A380741 1,2
%A A380741 _Davide Rotondo_, Jan 31 2025
%E A380741 More terms from _Amiram Eldar_, Jan 31 2025