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 A047692 #7 Mar 07 2020 02:03:00 %S A047692 1,1,2,2,8,120,240,720,5760,362880,3628800,57600,691200,6227020800, %T A047692 830269440,261534873600,20922789888000,355687428096000, %U A047692 914624815104000,426824913715200,4742499041280000,51090942171709440000,3784514234941440000 %N A047692 Denominators of coefficients in Taylor series for exp(tan(x)). %D A047692 CRC Standard Mathematical Tables and Formulae, 30th ed. 1996, p. 42. %e A047692 1 + 1*x + (1/2)*x^2 + (1/2)*x^3 + (3/8)*x^4 + (37/120)*x^5 + (59/240)*x^6 + (137/720)*x^7 + (871/5760)*x^8 + ... %Y A047692 Cf. A047691, A006229. %K A047692 nonn,easy,frac %O A047692 0,3 %A A047692 _N. J. A. Sloane_