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.

A189040 Decimal expansion of (e+sqrt(-4+e^2))/2.

Original entry on oeis.org

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

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Author

Clark Kimberling, Apr 15 2011

Keywords

Comments

Decimal expansion of the shape (= length/width = (e+sqrt(-4+e^2))/2) of the greater e-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

			2.2796103731105126266020168769161733623002084362...
		

Crossrefs

Programs

  • Mathematica
    r = E; t = (r + (-4 + r^2)^(1/2))/2; FullSimplify[t]
    N[t, 130]
    RealDigits[N[t, 130]][[1]]
    ContinuedFraction[t, 120]
    RealDigits[(E+Sqrt[E^2-4])/2,10,150][[1]] (* Harvey P. Dale, Oct 17 2013 *)

Extensions

Corrected by Harvey P. Dale, Oct 17 2013