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 A096717 #9 Nov 19 2016 03:10:15
%S A096717 1,-1,13,-341,18649,-177761,1087433,-4043494549,1674761567,
%T A096717 -284891766539657,106410874319325461,-48402125366670946877,
%U A096717 26344930021064765797249,-27048608191991004321089,6237195766537863970288933,-16102066950215127630856787159,2258820895862623437612519923989
%N A096717 Numerators of terms in series expansion of arcsin(arctan(x)).
%H A096717 G. C. Greubel, <a href="/A096717/b096717.txt">Table of n, a(n) for n = 0..200</a>
%e A096717 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 A096717 Numerator[Take[CoefficientList[Series[ArcSin[ArcTan[x]], {x,0,50}], x], {2, -1, 2}]] (* _G. C. Greubel_, Nov 17 2016 *)
%Y A096717 Cf. A096718, A096664, A096671, A096712, A096716, A045688, A045689, A096719, A096720, A096721, A096722.
%K A096717 sign,frac
%O A096717 0,3
%A A096717 _N. J. A. Sloane_, Aug 15 2004