login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A054399
Decimal expansion of the constant Product_{i=1..infinity} (1-3/(2*(i+1)))^(1/2^i).
2
3, 8, 1, 6, 8, 8, 3, 3, 8, 3, 3, 9, 6, 8, 5, 3, 0, 1, 3, 0, 1, 4, 1, 7, 9, 9, 7, 9, 7, 7, 7, 4, 5, 0, 3, 6, 4, 4, 3, 5, 8, 9, 8, 0, 2, 7, 4, 1, 8, 7, 6, 7, 5, 5, 3, 9, 5, 2, 9, 0, 6, 0, 4, 7, 6, 8, 9, 9, 4, 7, 6, 6, 0, 8, 8, 8, 1, 9, 7, 5, 8, 6, 9, 7, 5, 7, 0, 3, 7, 6, 1, 6, 4, 4, 2, 2, 8, 0, 6, 7, 9, 9, 7, 7, 1
OFFSET
0,1
REFERENCES
D.-Z. Du and F. K. Hwang, Combinatorial Group Testing and Its Applications, World Scientific, 2nd ed., 2000; p. 37.
EXAMPLE
.381688338339685...
MATHEMATICA
Exp[2*Derivative[1, 0][PolyLog][0, 1/2] - Derivative[0, 1, 0][LerchPhi][1/2, 0, 1/2]/2] // RealDigits[#, 10, 105]& // First (* Jean-François Alcover, Feb 19 2013 *)
PROG
(PARI)\p 500; prodinf(n=1, ((1-3/(2*(n+1)))^(1/2^n)))
CROSSREFS
Sequence in context: A247392 A219995 A021266 * A013676 A199270 A131563
KEYWORD
nonn,easy,cons
AUTHOR
N. J. A. Sloane, May 22 2000
EXTENSIONS
More terms from Jason Earls, Jun 28 2001
STATUS
approved