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A054400 Decimal expansion of 4 * Product_{i=1..inf} ((1-3/(2*(i+1)))^(1/2^i). 1
1, 5, 2, 6, 7, 5, 3, 3, 5, 3, 3, 5, 8, 7, 4, 1, 2, 0, 5, 2, 0, 5, 6, 7, 1, 9, 9, 1, 9, 1, 0, 9, 8, 0, 1, 4, 5, 7, 7, 4, 3, 5, 9, 2, 1, 0, 9, 6, 7, 5, 0, 7, 0, 2, 1, 5, 8, 1, 1, 6, 2, 4, 1, 9, 0, 7, 5, 9, 7, 9, 0, 6, 4, 3, 5, 5, 2, 7, 9, 0, 3, 4, 7, 9, 0, 2, 8, 1, 5, 0, 4, 6, 5, 7, 6, 9, 1, 2, 2, 7, 1, 9, 9, 0, 8 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

D.-Z. Du and F. K. Hwang, Combinatorial Group Testing and Its Applications, World Scientific, 2nd ed., 2000; p. 37.

LINKS

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

EXAMPLE

1.52675335335...

MATHEMATICA

digits = 105; 4*NProduct[ (1-3/(2*(i+1)))^(1/2^i), {i, 1, Infinity}, WorkingPrecision -> digits+5, NProductFactors -> 4*digits] // RealDigits[#, 10, digits]& // First (* Jean-Fran├žois Alcover, Mar 07 2013 *)

CROSSREFS

4*A054399.

Sequence in context: A158624 A021659 A011506 * A035568 A321074 A318384

Adjacent sequences:  A054397 A054398 A054399 * A054401 A054402 A054403

KEYWORD

nonn,easy,cons

AUTHOR

N. J. A. Sloane, May 22 2000

EXTENSIONS

More terms from David Wasserman, Mar 04 2002

STATUS

approved

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Last modified August 4 16:34 EDT 2020. Contains 336202 sequences. (Running on oeis4.)