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.

A340422 Decimal expansion of Integral_{x=0..Pi/2, y=0..Pi/2} log(1 + 2*sin(x)^2 + 2*sin(y)^2) dy dx.

Original entry on oeis.org

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

Views

Author

Vaclav Kotesovec, Jan 07 2021

Keywords

Examples

			2.551698806403924360993561678605629314325436926549295727591221339383517201757...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[N[Pi*Integrate[(Log[1 + Sqrt[1 + 2/(3 - 2*Cos[x]^2)]] + Log[(1 + 2*Sin[x]^2)/4]/2), {x, 0, Pi/2}], 120], 10, 110][[1]]

Formula

Equals Pi * Integral_{x=0..Pi/2} (log(1 + sqrt(1 + 2/(3 - 2*cos(x)^2))) + log((1 + 2*sin(x)^2)/4)/2) dx.
Equals limit_{n->infinity} Pi^2 * log(A067518(n))/(4*n^2) - Pi^2*log(2)/4 - G*Pi, where G is Catalan's constant A006752.