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A143280 Decimal expansion of Sum[1/n!!,{n,0,Infinity}]. 3
3, 0, 5, 9, 4, 0, 7, 4, 0, 5, 3, 4, 2, 5, 7, 6, 1, 4, 4, 5, 3, 9, 4, 7, 5, 4, 9, 9, 2, 3, 3, 2, 7, 8, 6, 1, 2, 9, 7, 7, 2, 5, 4, 7, 2, 6, 3, 3, 5, 3, 4, 0, 2, 0, 9, 2, 9, 9, 7, 1, 8, 7, 7, 9, 8, 0, 5, 4, 4, 2, 8, 1, 9, 6, 8, 4, 6, 1, 3, 5, 3, 5, 7, 4, 8, 1, 8, 5, 7, 4, 4, 8, 3, 4, 9, 7, 8, 2, 8, 3, 1, 5, 0, 1, 5 (list; constant; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Also decimal expansion of  Sum[n!!/n!,{n,1,Infinity}]. - Michel Lagneau, Dec 24 2011

LINKS

Eric Weisstein's World of Mathematics, Double Factorial

FORMULA

Sqrt[E] + Sqrt[(E*Pi)/2]*Erf[1/Sqrt[2]]

EXAMPLE

3.0594074053425761445...

CROSSREFS

Sequence in context: A103229 A181835 A076296 * A088521 A022837 A088969

Adjacent sequences:  A143277 A143278 A143279 * A143281 A143282 A143283

KEYWORD

nonn,cons

AUTHOR

E. W. Weisstein (eric(AT)weisstein.com), Aug 04, 2008

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Last modified February 23 09:08 EST 2012. Contains 206628 sequences.