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A247551 Decimal expansion of Product_{k>=2} 1/(1-1/k!). 17
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 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..105.

Steven R. Finch, Mathematical Constants II, Encyclopedia of Mathematics and Its Applications, Cambridge University Press, Cambridge, 2018, p. 269.

A. Knopfmacher, A. M. Odlyzko, B. Pittel, L. B. Richmond, D. Stark, G. Szekeres, N. C. Wormald, The Asymptotic Number of Set Partitions with Unequal Block Sizes, The Electronic Journal of Combinatorics, Volume 6 (1999), Research Paper #R2.

FORMULA

Product_{k>=2} 1/(1-1/k!).

Equals lim n -> infinity A005651(n) / n!.

EXAMPLE

2.5294774720791526481801161542539542411787023948459973375849349825...

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-Fran├žois Alcover, Nov 02 2020 *)

PROG

(PARI) default(realprecision, 150); 1/prodinf(k=2, 1 - 1/k!) \\ Vaclav Kotesovec, Sep 21 2014

CROSSREFS

Cf. A005651, A035341, A072605, A140585, A183239, A209668, A261600, A292713, A320566, A327827, A335643.

Sequence in context: A131201 A070633 A266256 * A336853 A273580 A272679

Adjacent sequences:  A247548 A247549 A247550 * A247552 A247553 A247554

KEYWORD

nonn,cons,easy

AUTHOR

Vaclav Kotesovec, Sep 19 2014

STATUS

approved

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Last modified July 28 05:31 EDT 2021. Contains 346317 sequences. (Running on oeis4.)