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.

Showing 1-5 of 5 results.

A247551 Decimal expansion of Product_{k>=2} 1/(1-1/k!).

Original entry on oeis.org

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

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Author

Vaclav Kotesovec, Sep 19 2014

Keywords

Examples

			2.5294774720791526481801161542539542411787023948459973375849349825...
		

Crossrefs

Programs

  • Maple
    evalf(1/product(1-1/k!,k=2..infinity),100); # Vaclav Kotesovec, Sep 19 2014
  • Mathematica
    digits = 105;
    RealDigits[NProduct[1/(1-1/k!), {k, 2, Infinity}, WorkingPrecision -> digits+10, NProductFactors -> digits], 10, digits][[1]] (* Jean-François Alcover, Nov 02 2020 *)
  • PARI
    default(realprecision,150); 1/prodinf(k=2,1 - 1/k!) \\ Vaclav Kotesovec, Sep 21 2014

Formula

Product_{k>=2} 1/(1-1/k!).
Equals lim_{n -> oo} A005651(n) / n!.
Equals 1/A282529. - Amiram Eldar, Sep 15 2023

A238695 Decimal expansion of Product_{k>=0} (1+1/k!).

Original entry on oeis.org

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

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Author

Frederick Reckless, Mar 03 2014

Keywords

Comments

Conjectured to be irrational, transcendental and normal, none have been shown. Product is sometimes taken from n=1, leading to half the stated value.

Examples

			7.3643082723672572563727725096310530956542568360689...
		

Crossrefs

Cf. A387175 (continued fraction).

Programs

Extensions

Added more digits from b-file, so as to cover exactly three full rows of text. - Lucian Craciun, Feb 22 2017

A369994 Decimal expansion of Product_{k>=2} (1 - 1/k!!).

Original entry on oeis.org

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

Views

Author

Ilya Gutkovskiy, Mar 30 2024

Keywords

Examples

			0.26294413828698825249397612947579574217...
		

Crossrefs

A370424 Decimal expansion of Product_{k>=2} (1 - 1/(2*k-1)!!).

Original entry on oeis.org

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

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Author

Ilya Gutkovskiy, Mar 30 2024

Keywords

Examples

			0.61558002800838914113852450027455396226...
		

Crossrefs

A342574 Remainder of e when the Dirichlet series for e is converted to an infinite product (negated).

Original entry on oeis.org

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

Views

Author

Michael P. May, Mar 27 2021

Keywords

Comments

Remainder term when the Dirichlet series representation of e is converted to an infinite product via the Euler Product Formula method. The remainder can be calculated via the infinite series found at the top of page 2 of "A Non-Sieving Application ..." (see links) or by the much simpler method A001113*A282529-2.

Examples

			-0.925358356236040633370884166370763828049565...
		

Crossrefs

Cf. A001113 (e), A282529.

Formula

Equals A001113*A282529-2.

Extensions

More digits from Alois P. Heinz, Mar 31 2021
Showing 1-5 of 5 results.