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 A215670 #16 Sep 22 2012 10:36:01
%S A215670 1,0,7,1,2,6,9,4,4,8,7,2,9,5,2,9,9,6,1,1,2,0,2,9,4,8,1,3,4,7,4,1,9,1,
%T A215670 7,4,8,4,3,3,2,1,3,9,8,2,6,3,3,6,6,1,2,8,9,0,4,4,7,3,5,5,8,4,2,6,4,7,
%U A215670 9,8,6,2,7,2,1,1,3,1,1,6,9,6,6,8,5,8,5,1,8,7,7,9,6,2,3,5,4,7,3,7,5,9,2,3
%N A215670 Decimal expansion of the min value of F(x) := cos(sin(x)) - sin(cos(x)), x in R.
%C A215670 We note that dF(x)/dx = (-1/2)*h(x)*sin(2*x), x in (0,Pi/2), where h(x) is the function discussed in comments to A215668 (see also Witula et al.'s reference for more informations).
%D A215670 R. Witula, D. Jama, E. Hetmaniok, D. Slota, On some inequality of the trigonometric type, Zeszyty Naukowe Politechniki Slaskiej - Matematyka-Fizyka (Science Fascicle of Silesian Technical University - Math.-Phys.), 92 (2010), 83-92.
%F A215670 F(z) = cos(sin(z)) - sin(cos(z)) = (cos(z) - sin(z))*(cos(cos(z)) + sin(sin(z)))*cos(cos(z))/(cos(sin(z)) + sin(cos(z)))*cos(z) = cos(2*z)*cos(cos(z))^2/(cos(sin(z)) + sin(cos(z)))*cos(z)^2 = (1 - tan(z)^2)*cos(cos(z))^2/(cos(sin(z)) + sin(cos(z))), where z := A215668.
%e A215670 min{F(x): x in R} = F(z) = 0.1071269448729529961...
%Y A215670 Cf. A215668, A215832, A215833, A168546, A216891.
%K A215670 nonn,cons
%O A215670 0,3
%A A215670 _Roman Witula_, Aug 20 2012