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A080219 Decimal expansion of exponential factorial constant Sum_{n>=1} 1/A049384(n). 2
1, 6, 1, 1, 1, 1, 4, 9, 2, 5, 8, 0, 8, 3, 7, 6, 7, 3, 6, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This is a Liouville number and therefore transcendental.

REFERENCES

Contributed by Jonathan Sondow.

LINKS

Table of n, a(n) for n=1..100.

J. Sondow, MathWorld: Exponential Factorial

J. Sondow, Irrationality measures, irrationality bases, and a theorem of Jarnik, arXiv 2004; see L_4 in Example 4.

Wikipedia, Exponential factorial

Wikipedia, Liouville number

EXAMPLE

1/1 + 1/2 + 1/9 + 1/262144 + ... = 1.611114925808376736111...

MATHEMATICA

eFac[1] = 1; eFac[n_] := eFac[n] = n^eFac[n-1]; Clear[s]; s[m_] := s[m] = RealDigits[Sum[1/eFac[n], {n, 1, m}], 10, 100] // First; s[m = 1]; While[s[m] != s[m - 1], m++]; s[m] (* Jean-Fran├žois Alcover, Feb 08 2013 *)

CROSSREFS

Cf. A049384, A167155.

Sequence in context: A234959 A167155 A268731 * A040037 A009194 A007732

Adjacent sequences:  A080216 A080217 A080218 * A080220 A080221 A080222

KEYWORD

nonn,cons

AUTHOR

Eric W. Weisstein, Feb 06 2003

STATUS

approved

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Last modified December 8 22:51 EST 2016. Contains 278957 sequences.