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.

A234473 Decimal expansion of exp(exp(1)-1).

Original entry on oeis.org

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

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Author

Richard R. Forberg, Dec 26 2013

Keywords

Comments

Derived from an infinite sum of the Bell numbers (see formula below).
May also be written as exp(exp(1))/exp(1) = e^e/e.

Examples

			5.5749415247608806239669759227404843057060930975947002119298237838570...
		

Crossrefs

Cf. A000110, A001113 (e), A073226 (e^e), A274169.

Programs

  • Mathematica
    RealDigits[Exp[E-1], 10, 100][[1]] (* Amiram Eldar, Dec 04 2021 *)
  • PARI
    exp(exp(1)-1)

Formula

Equals Sum_{n>=0} Bell(n)/n!, where Bell(n) = A000110(n).
Equals Product_{k=1..oo} exp(1/k!). - Christoph B. Kassir, Dec 04 2021