A184084 Decimal expansion of product_{p=primes} (1-1/(2^p+1)).

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.

Links

Table of n, a(n) for n=0..80.

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

Adjacent sequences: A184081 A184082 A184083 * A184085 A184086 A184087

Keyword

cons,nonn

Author

R. J. Mathar, Jan 09 2011

Status

approved