

A213007


Decimal expansion of the Brun's quadruple primes constant


0




OFFSET

0,1


COMMENTS

Infinite sum of the inverse values of p, p+2, p+6, and p+8, where p ranges over all elements of A007530.
The 9th digit is probably 0.


LINKS

Table of n, a(n) for n=0..7.
T. R. Nicely, Enumeration to 1.6e15 of the prime quadruplets.
Wikipedia, Brun's theorem.
Wikipedia, Prime quadruplet.


FORMULA

Sum[n=1,2,...] (1/c(n) + 1/(c(n)+2) + 1/(c(n)+6) + 1/(c(n)+8)), where c(n) = A007530(n).


EXAMPLE

0.8705883800[+5]


CROSSREFS

Cf. A007530, A194098, A194098, A065421.
Sequence in context: A051762 A247017 A198112 * A155094 A261303 A259348
Adjacent sequences: A213004 A213005 A213006 * A213008 A213009 A213010


KEYWORD

nonn,cons,hard


AUTHOR

Stanislav Sykora, Jun 01 2012


STATUS

approved



