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 A229174 #17 Dec 15 2024 05:24:53
%S A229174 0,5,0,4,1,3,7,6,0,4,5,5,9,3,5,9,9,7,2,1,2,2,0,0,0,9,1,2,7,5,1,3,6,1,
%T A229174 0,9,6,2,1,4,9,8,7,8,5,4,0,0,9,1,0,3,6,7,8,7,3,2,8,4,9,4,8,6,5,3,5,6,
%U A229174 3,4,4,8,0,4,0,1,3,4,9,2,6,0,7,9,3,3,5,0,1,6,6,0,4,8,6,3,1,7,6,8,3,0,9,7,6,2,8
%N A229174 Decimal expansion of Integral_{x=0..Infinity} x*cos(x)/(1+x^2).
%D A229174 Steven R. Finch, Mathematical Constants, Cambridge, 2003, pp. 424-425.
%F A229174 Equals (e^2*Ei(-1)+Ei(1))/(2*e) where Ei is the exponential integral function. - _Jean-François Alcover_, Feb 19 2014
%e A229174 0.050413760455935997212200091275136109621498785400910367873
%t A229174 Join[{0}, (E^2*ExpIntegralEi[-1] + ExpIntegralEi[1])/(2*E) // RealDigits[#, 10, 106]& // First] (* _Jean-François Alcover_, Feb 19 2014 *)
%Y A229174 Cf. A216184, A086056.
%K A229174 nonn,cons
%O A229174 0,2
%A A229174 _N. J. A. Sloane_, Sep 28 2013