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 A085666 #14 Aug 06 2024 05:20:02 %S A085666 8,6,3,5,1,8,8,5,4,8,7,8,0,5,8,8,8,1,9,8,7,0,1,5,5,9,3,1,3,6,4,3,1,8, %T A085666 5,0,7,7,2,2,4,7,6,0,5,8,1,8,5,7,3,4,3,0,5,7,7,5,7,2,6,9,5,4,3,0,3,8, %U A085666 8,5,3,4,8,3,4,6,5,8,6,4,3,9,2,9,6,5,2,4,3,0,3,4,0,0,8,7,4,7,5 %N A085666 Decimal expansion of -tan(tan(tan(1))). %H A085666 Jens Blanck, <a href="https://doi.org/10.1007/3-540-45335-0_24">Exact real arithmetic systems: results of competition</a>, pp. 389-393 of J. Blanck et al., eds., Computability and Complexity in Analysis (CCA 2000), Lect. Notes Computer Science, Springer-Verlag, 2001; <a href="https://citeseerx.ist.psu.edu/pdf/995022a4b87d399debf7b5bda0b52a3615a8499f">alternative link</a>. %e A085666 0.86351885487805888198701559313643185077224760581857... %t A085666 RealDigits[Tan[Tan[Tan[1]]], 10, 120][[1]] (* _Amiram Eldar_, Jun 08 2023 *) %o A085666 (PARI) -tan(tan(tan(1))) \\ _Charles R Greathouse IV_, Mar 25 2014 %Y A085666 Cf. A049471. %K A085666 cons,nonn %O A085666 0,1 %A A085666 _N. J. A. Sloane_, Jul 15 2003