1,2

Table of n, a(n) for n=1..102.

Alexei Kourbatov, On the distribution of maximal gaps between primes in residue classes, arXiv:1610.03340 [math.NT], 2016-2018.

Eric Weisstein's World of Mathematics, Twin Primes Constant.

Eric Weisstein's World of Mathematics, Prime Constellation.

Equals 2*A005597 (in the sense of the corresponding decimal numbers).

1.320323631693739147855624220...

(PARI) 2 * prodeulerrat(1-1/(p-1)^2, 1, 3) \\ Amiram Eldar, Mar 16 2021

Cf. A005597.

Sequence in context: A286889 A286368 A190710 * A278499 A231132 A290327

Adjacent sequences: A114904 A114905 A114906 * A114908 A114909 A114910

nonn,cons

Eric W. Weisstein, Jan 06 2006

Corrected offset and edited by M. F. Hasler, Dec 09 2008

approved