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 A047690 #8 Mar 07 2020 01:53:28 %S A047690 1,2,6,720,40320,907200,479001600,87178291200,5230697472000, %T A047690 6402373705728000,221172909834240000,281000181944401920000, %U A047690 620448401733239439360000,403291461126605635584000000,76222086152928465125376000000,24113896346562823512391680000000 %N A047690 Denominators of coefficients in Taylor series for exp(cos(x)-1). %D A047690 CRC Standard Mathematical Tables and Formulae, 30th ed. 1996, p. 42. %e A047690 1 - (1/2)*x^2 + (1/6)*x^4 - (31/720)*x^6 + (379/40320)*x^8 - (1639/907200)*x^10 + ... %Y A047690 Cf. A047689, A005046. %Y A047690 Cf. A097322. %K A047690 nonn,easy,frac %O A047690 0,2 %A A047690 _N. J. A. Sloane_