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 A096722 #7 Nov 19 2016 03:13:32
%S A096722 1,1,1,30,756,75600,199584,54486432000,2421619200,151227648000,
%T A096722 5913303492096000,5203707073044480000,512936840057241600000,
%U A096722 5041143264082570444800000,1238175538546596249600000,11695452372671563431936000000,33500453776280426294437478400000,44295044437526341433756221440000000
%N A096722 Denominators of terms in series expansion of arcsin(arctan(x)) - arctan(arcsin(x)).
%H A096722 G. C. Greubel, <a href="/A096722/b096722.txt">Table of n, a(n) for n = 0..200</a>
%e A096722 arcsin(arctan(x)) - arctan(arcsin(x)) = -1/30*x^7 + 13/756*x^9 - 2329/75600*x^11 + 3749/199584*x^13 - 1405132357/54486432000*x^15 + ...
%t A096722 Denominator[Take[CoefficientList[Series[ArcSin[ArcTan[x]] - ArcTan[ArcSin[x]], {x,0,40}], x], {2,-1,2}]] (* _G. C. Greubel_, Nov 18 2016 *)
%Y A096722 Cf. A096721, A096717, A096718, A096664, A096671, A096712, A096716, A045688, A045689, A096719, A096720.
%K A096722 nonn,frac
%O A096722 0,4
%A A096722 _N. J. A. Sloane_, Aug 15 2004