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.

A261813 Decimal expansion of (Pi/4)^N*(N^N/N!)^2 for N = 3.

Original entry on oeis.org

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

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Author

Stanislav Sykora, Nov 19 2015

Keywords

Comments

The general expression is a lower bound (due to H. Minkowski) on the discriminant of a number field of degree N.
The corresponding value for N = 2 matches A091476.

Examples

			9.8105797308761149773968028142000508257040952102995848563504202594...
		

References

  • B. Mazur, Algebraic Numbers, in The Princeton Companion to Mathematics, Editor T. Gowers, Princeton University Press, 2008, Section IV.1, page 330.

Crossrefs

Cf. A000796, A091476 (N=2).

Programs

  • Mathematica
    n = 3; First@ RealDigits[N[(Pi/4)^n (n^n/n!)^2, 120]] (* Michael De Vlieger, Nov 19 2015 *)
  • PARI
    N=3;(Pi/4)^N*(N^N/N!)^2

Formula

Equals 81*Pi^3/256.