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.

A189039 Decimal expansion of (Pi+sqrt(-4+Pi^2))/2.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Apr 16 2011

Keywords

Comments

Decimal expansion of the shape (= length/width = (Pi+sqrt(-4+Pi^2))/2) of the greater Pi-contraction rectangle.
See A188738 for an introduction to lesser and greater r-contraction rectangles, their shapes, and partitioning these rectangles into a sets of squares in a manner that matches the continued fractions of their shapes.

Examples

			2.78215964977951614931609799583128287194190...
		

Crossrefs

Programs

  • Mathematica
    r = Pi; t = (r + (-4 + r^2)^(1/2))/2; FullSimplify[t]
    N[t, 130]
    RealDigits[N[t, 130]][[1]] (*A189039*)
    ContinuedFraction[t, 120]  (*A188804*)
  • PARI
    (Pi+sqrt(-4+Pi^2))/2 \\ Michel Marcus, Jun 14 2015

Formula

Equals A000796-A189044. - Alois P. Heinz, Jul 21 2022