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 A066747 #12 Oct 25 2019 21:35:52
%S A066747 7,3,4,1,2,1,5,1,5,4,0,8,2,8,6,1,2,0,6,0,6,2,7,8,2,8,8,4,5,7,2,3,2,1,
%T A066747 4,9,2,2,8,5,6,5,0,4,6,6,1,1,6,1,3,9,9,1,4,0,6,6,0,3,4,1,2,5,5,5,9,5,
%U A066747 4,0,4,5,0,4,3,7,0,0,3,1,0,8,0,6,4,3,0,6,3,4,9,2,6,9,3,2,5,6,1,6
%N A066747 Decimal expansion of the "binary" Copeland-Erdős constant 0.734121515408286120606...: concatenate primes in base two.
%C A066747 The "binary" Copeland-Erdős constant is obtained by concatenating the binary representations of the primes = 0.(10)(11)(101)(111)(1011)(1101)(10001)...
%C A066747 A theorem of Copeland & Erdős proves that this constant is 2-normal. - _Charles R Greathouse IV_, Feb 06 2015
%H A066747 A. H. Copeland and P. Erdős, <a href="http://www.renyi.hu/~p_erdos/1946-01.pdf">Note on normal numbers</a>, Bull. Amer. Math. Soc. 52 (1946), pp. 857-860.
%t A066747 a = {}; Do[ a = Append[a, IntegerDigits[ Prime[n], 2]], {n, 1, 100}]; RealDigits[ N[ FromDigits[ {Flatten[a], 0}, 2], 100]]
%o A066747 (PARI) sum(n=1,25,(p=prime(n))*.5^s+=logint(p,2)+1,s=0)+printf("Accurate to %.0E",.5^s) \\ _M. F. Hasler_, Oct 25 2019
%Y A066747 Cf. A066748 (continued fraction), A191232 (binary digits).
%Y A066747 Cf. A033308 (base-10 Copeland-Erdős constant).
%K A066747 nonn,cons,base
%O A066747 0,1
%A A066747 _Robert G. Wilson v_, Jan 16 2002