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 A045689 #7 Feb 26 2018 00:54:30 %S A045689 1,1,1,30,756,75600,7392,54486432000,4358914560,1905468364800, %T A045689 7602818775552000,6690480522485760000,4616431560515174400000, %U A045689 226851446883715670016000000,127036810254880775208960000,2210440498434925488635904000000,646080179971122507107008512000000 %N A045689 Denominators of expansion of tan(sin(x)) - sin(tan(x)). %D A045689 V. I. Arnold, Huygens and Barrow, Newton and Hooke, Birkhäuser, Basel, 1990. %e A045689 1/30*x^7 + 29/756*x^9 + 1913/75600*x^11 + O(x^12). %Y A045689 Cf. A045688, A096664, A096671, A096712, A096716. %K A045689 nonn %O A045689 0,4 %A A045689 _N. J. A. Sloane_