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.

A377981 Decimal expansion of G/2 - Pi*log(2)/8, where G = A006752.

Original entry on oeis.org

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

Views

Author

Stefano Spezia, Nov 13 2024

Keywords

Examples

			0.18578453580065924121471564518649031196975172459...
		

References

  • Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 1.7.2, p. 55.

Crossrefs

Programs

  • Mathematica
    RealDigits[Catalan/2-Pi Log[2]/8,10,100][[1]]

Formula

Equals Sum_{n>=0} (-1)^(n+1)/(2*n + 1) Sum_{k=0..n-1} 1/(2*k + 1) (see Finch).
Equals Integral_{x=0..Pi/4} x*tan(x) dx (see Shamos).
Equals A006752/2 - A102886.