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 A277774 #17 Dec 01 2024 10:04:33
%S A277774 1,0,9,7,8,5,1,0,3,9,6,7,9
%N A277774 Decimal expansion of the prime triples constant, also known as Brun's constant B_{3a} = Sum (1/p + 1/(p+2) + 1/(p+6)) as p runs through the initial members of prime triples A022004.
%D A277774 Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 2.14, p. 133.
%H A277774 Thomas R. Nicely, <a href="https://faculty.lynchburg.edu/~nicely/counts.html">Prime Constellations Research Project</a> (Mar 16 2010).
%e A277774 1.097851039679...
%Y A277774 Cf. A022004, A065421, A194098, A213007, A277775.
%K A277774 nonn,cons,hard,more
%O A277774 1,3
%A A277774 _Martin Renner_, Oct 29 2016
%E A277774 Offset corrected by _Rick L. Shepherd_, Nov 03 2016