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.

A188739 Decimal expansion of e+sqrt(e^2-1).

Original entry on oeis.org

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

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Author

Clark Kimberling, Apr 11 2011

Keywords

Comments

Decimal expansion of the shape of a greater 2e-contraction rectangle; see A188738 for an introduction to lesser and greater r-contraction rectangles, their shapes, and the partitioning of these rectangles into sets of squares in a manner that matches the continued fractions of their shapes.

Examples

			5.24594005277075985646114668616376972685147198530... = 1/A188738 .
		

Crossrefs

Cf. A001113, A188738 (inverse), A188627 (continued fraction), A365927.

Programs

  • Magma
    SetDefaultRealField(RealField(100)); Exp(1) + Sqrt(Exp(2) -1); // G. C. Greubel, Nov 01 2018
  • Mathematica
    r = 2 E; t = (r + (-4 + r^2)^(1/2))/2; FullSimplify[t]
    N[t, 130]
    RealDigits[N[t, 130]][[1]] (* A188739 *)
    ContinuedFraction[t, 120] (* A188627 *)
    RealDigits[E+Sqrt[E^2-1],10,150][[1]] (* Harvey P. Dale, Oct 25 2020 *)
  • PARI
    default(realprecision, 100); exp(1) + sqrt(exp(2) - 1) \\ G. C. Greubel, Nov 01 2018
    

Formula

e+sqrt(-1+e^2), with continued fraction A188627.
Equals exp(A365927). - Amiram Eldar, Oct 18 2023