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 A135702 #8 Nov 02 2016 11:32:18
%S A135702 3,6,6,9,7,2,7,3,0,2,7,8,7,3,3,5,7,8,7,9,3,2,8,5,0,3,3,8,8,4,7,9,3,3,
%T A135702 4,7,7,3,4,4,8,4,7,9,9,2,9,1,0,9,3,8,8,5,4,5,3,2,9,6,7,4,0,2,4,4,7,9,
%U A135702 4,4,9,6,7,3,9,9,4,4,9,1,6,2,9,7,3,3,4,4,9,7,3,9,3,3,5,6,8,0,0,7,8,4,8,6,5
%N A135702 Decimal expansion of 3*Sum_{k=1..inf} 1/(10^k-1).
%C A135702 Equals: 3*A073668, also A065444/3.
%H A135702 G. C. Greubel, <a href="/A135702/b135702.txt">Table of n, a(n) for n = 0..2500</a>
%e A135702 0.36697273...
%t A135702 RealDigits[9*N[ (1/3) Sum[1/(10^k - 1), {k, 1, Infinity}], 120]] [[1]]
%o A135702 (PARI) 3*suminf(k=1, 1/(10^k-1)) \\ _Michel Marcus_, Oct 30 2016
%Y A135702 Cf. A073668, A065444.
%K A135702 nonn,cons
%O A135702 0,1
%A A135702 _Eric Desbiaux_, Mar 03 2008