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 A096718 #7 Nov 19 2016 03:10:41
%S A096718 1,6,120,5040,362880,4435200,32947200,145297152000,69701632000,
%T A096718 13516122267648000,5676771352412160000,2872446304320552960000,
%U A096718 1723467782592331776000000,1935799013407707050803200,485144691014524112732160000,1353553687930522274522726400000,204193242064947360270857011200000
%N A096718 Denominators of terms in series expansion of arcsin(arctan(x)).
%H A096718 G. C. Greubel, <a href="/A096718/b096718.txt">Table of n, a(n) for n = 0..200</a>
%e A096718 arcsin(arctan(x)) = x - 1/6*x^3 + 13/120*x^5 - 341/5040*x^7 + 18649/362880*x^9 - 177761/4435200*x^11 + ...
%t A096718 Denominator[Take[CoefficientList[Series[ArcSin[ArcTan[x]], {x,0,40}], x], {2,-1,2}]] (* _G. C. Greubel_, Nov 17 2016 *)
%Y A096718 Cf. A096717, A096664, A096671, A096712, A096716, A045688, A045689, A096721, A096722.
%K A096718 nonn,frac
%O A096718 0,2
%A A096718 _N. J. A. Sloane_, Aug 15 2004