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 A072101 #9 Mar 13 2021 10:05:45
%S A072101 0,1,1,7,1,1,1,3,1,1,7,1,15,1,1,5,1,1,6,1,1,12,2,1,52,6,3,2,1,7,1,1,4,
%T A072101 2,1,5,1,1,1,7,2,1,5,1,13,3,1,1,4161,1,1,1,9,4,6,1,12,2,9,3,1,4,3,1,6,
%U A072101 3,2,1,3,4,2,2,3,93,3,1,10,1,2,1,7,4,4,2,1,1,2,2,10,1,1,2,3,3,1,1,3,1
%N A072101 Continued fraction expansion of Product_{p prime} (1 - 1/(p^2-1)).
%H A072101 Gerhard Niklasch, <a href="http://www.gn-50uma.de/alula/essays/Moree/Moree-details.en.shtml#t15-feller">Some number-theoretical constants: 1000-digit values</a>.
%t A072101 (* c= the value at the link above; *) ContinuedFraction[c, 100]
%o A072101 (PARI) contfrac(prodeulerrat(1 - 1/(p^2-1))) \\ _Amiram Eldar_, Mar 13 2021
%Y A072101 Cf. A065469.
%K A072101 cofr,nonn
%O A072101 0,4
%A A072101 _Robert G. Wilson v_, Jun 18 2002