A209328 Decimal expansion of the sum of the inverse twin prime products.

1, 0, 7, 9, 8, 3, 9, 7, 4, 9, 5

Offset

0,3

Comments

Summation up to the lesser prime(100000) gives 0.1079839703839.., summation up to the lesser prime(5000000) gives 0.10798397490956.. and summation up to the lesser prime(100000000) gives 0.107983974949..

The constant splits Brun's constant B=A065421 into two portions: define L=Sum_{n>=1} 1/A001359(n) and U=Sum_{n>=1} 1/A006512(n). Then B=U+L and this constant here = (L-U)/2. This leads to the estimates L=1.059064 and U=0.843096. - R. J. Mathar, Feb 05 2013

Links

Table of n, a(n) for n=0..10.

Example

0.10798397495... = 1/(3*5) + 1/(5*7) + 1/(11*13) + .. = Sum_{n>=1} 1/A037074(n).

Crossrefs

Cf. A001359, A006512, A037074, A065421.

Sequence in context: A256924 A348668 A259069 * A228049 A154943 A126041

Adjacent sequences: A209325 A209326 A209327 * A209329 A209330 A209331

Keyword

nonn,cons,more

Author

R. J. Mathar, Jan 19 2013

Status

approved