cp's OEIS Frontend

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.

A233382 Decimal expansion of the integral over dx/((1+x^2)(1+tan x)) in the limits 0 and Pi/2.

Original entry on oeis.org

5, 9, 7, 3, 8, 1, 8, 0, 9, 4, 5, 1, 8, 0, 3, 4, 8, 4, 6, 1, 3, 1, 1, 3, 2, 3, 5, 0, 9, 0, 8, 7, 3, 7, 6, 4, 3, 0, 6, 4, 3, 8, 5, 9, 0, 4, 2, 5, 5, 5, 6, 7, 3, 0, 7, 7, 0, 3, 2, 0, 7, 1, 6, 1, 5, 5, 0, 3, 1, 1, 0, 3, 3, 2, 4, 9, 8, 2, 4, 1, 2, 1, 7, 8, 9, 0, 9, 8, 9, 9, 0, 4, 0, 4, 4, 7, 4, 4, 4, 3, 7, 3, 3, 0, 0, 9
Offset: 0

Views

Author

R. J. Mathar, Dec 08 2013

Keywords

Examples

			0.59738180945180348461311323509087376430643859042555673077032071615503110332498…
		

Programs

  • Maple
    Digits := 60 :
    # Expand 1/(1+tan x) in a Taylor series around Pi/4 and exchange
    # summation and integration.
    for dd from 80 to 100 by 10 do
        taylor(1/(1+tan(z)),z=Pi/4,dd) ;
        gfun[seriestolist](%) ;
        c := evalf(%) ;
        x := 0.0 ;
        for i from 0 to nops(c)-1 do
            1/(1+zz^2)*op(i+1,c)*(zz-Pi/4)^i ;
            int(%,zz=0..Pi/2) ;
            x := x+evalf(%) ;
        end do:
        print(x) ;
    end do:
  • Mathematica
    RealDigits[ NIntegrate[ 1/((1+x^2)(1+Tan[x])),{x, 0, Pi/2}, WorkingPrecision -> 110], 10, 105][[1]] (* Robert G. Wilson v, Sep 29 2014 *)