A213007 Decimal expansion of Brun's quadruple primes constant.

8, 7, 0, 5, 8, 8, 3, 8

Offset: 0

Author

Stanislav Sykora, Jun 01 2012

Keywords

• nonn
• cons
• hard
• more

Comments

Infinite sum of the reciprocals of p, p+2, p+6, and p+8, where p ranges over all elements of A007530.

The 9th digit is probably 0.

Examples

			0.8705883800[+-5]
		

References

• Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 2.14, p. 133.

Links

• Thomas R. Nicely, Enumeration to 1.6e15 of the prime quadruplets.
• Wikipedia, Brun's theorem.
• Wikipedia, Prime quadruplet.

Crossrefs

Cf. A007530, A194098, A065421.

Formula

Sum_{n >= 1} (1/c(n) + 1/(c(n)+2) + 1/(c(n)+6) + 1/(c(n)+8)), where c(n) = A007530(n).