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A184084
Decimal expansion of product_{p=primes} (1-1/(2^p+1)).
3
6, 8, 3, 7, 9, 2, 8, 4, 2, 3, 5, 9, 4, 7, 4, 3, 6, 8, 9, 9, 4, 3, 6, 3, 6, 4, 3, 4, 1, 0, 7, 6, 3, 4, 4, 4, 3, 6, 8, 2, 2, 1, 0, 8, 7, 5, 8, 1, 8, 1, 7, 3, 5, 2, 6, 2, 9, 4, 7, 1, 2, 9, 8, 1, 0, 5, 5, 9, 9, 0, 4, 2, 3, 5, 5, 6, 5, 5, 7, 7, 7
OFFSET
0,1
COMMENTS
Inverse of the constant A184083.
FORMULA
Equals product_{p in A000040} (1-1/(2^p+1)) = 1/ product_p (1+2^(-p)) = product_{n>=1} (1-1/A098640(n)).
EXAMPLE
(1-1/5) *(1-1/9) *(1-1/33) * (1-1/129) *(1-1/2049)* ... = 0.6837928423594743689943636...
MATHEMATICA
RealDigits[Times@@Table[1-1/(2^p+1), {p, Prime[Range[1000]]}], 10, 100][[1]] (* Harvey P. Dale, Jul 23 2024 *)
CROSSREFS
Sequence in context: A021940 A316256 A054042 * A346402 A255728 A272488
KEYWORD
cons,nonn
AUTHOR
R. J. Mathar, Jan 09 2011
STATUS
approved