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 A061678 #20 Aug 29 2022 14:45:10
%S A061678 0,2,1,2,3,26,1,2,2,1,2,19682,1,1,1,2,2,1,26,3,2,1,2,7625597484986,1,
%T A061678 1,1,2,3,26,1,2,2,1,1,1,19682,2,1,2,2,1,26,3,2,1,2,
%U A061678 443426488243037769948249630619149892802,1,1,1,2,3,26,1,2,2,1,2,19682
%N A061678 Continued fraction for Sum_{n>=0} 1/3^(3^n).
%C A061678 The continued fraction has a "folded" overall structure. Apart from a(0) and from the record values of the form 3^(3^k)-1 (k >= 0), the only terms are 1 and 3. This follows from the theorem in Shallit's paper. - _Georg Fischer_, Aug 29 2022
%H A061678 Harry J. Smith, <a href="/A061678/b061678.txt">Table of n, a(n) for n = 0..382</a>
%H A061678 Jeffrey O. Shallit, <a href="https://doi.org/10.1016/0022-314X(82)90047-6">Simple Continued Fractions for Some Irrational Numbers II</a>, J. Number Theory 14 (1982), 228-231.
%e A061678 0.370421175633926798495743189411...
%t A061678 ContinuedFraction[Sum[1/3^(3^i), {i, 0, 5}]] (* _Michael De Vlieger_, Jul 01 2018 *)
%o A061678 (PARI) { allocatemem(932245000); default(realprecision, 8000); x=contfrac(suminf(n=0, 1/3^(3^n))); for (n=0, 382, write("b061678.txt", n, " ", x[n+1])) } \\ _Harry J. Smith_, Jul 26 2009
%Y A061678 Cf. A004200, A006464, A006465, A006466, A006467, A007400, A081771.
%K A061678 cofr,nonn
%O A061678 0,2
%A A061678 _Jason Earls_, Jun 23 2001