A109831 Greatest number of primes < prime(n) forming an arithmetic progression such that also prime(n) is a term.

1, 1, 2, 2, 1, 2, 2, 3, 4, 2, 1, 3, 3, 2, 4, 3, 2, 2, 2, 2, 3, 3, 2, 3, 3, 3, 3, 2, 3, 4, 4, 2, 3, 3, 3, 5, 3, 3, 4, 2, 3, 3, 3, 4, 3, 2, 3, 4, 3, 3, 3, 3, 4, 5, 3, 3, 4, 2, 3, 4, 4, 3, 5, 3, 3, 3, 2, 3, 3, 5, 3, 3, 4, 2, 3, 4, 4, 3, 3, 3, 4, 3, 3, 3, 4, 4, 3, 3, 5, 3, 4, 3, 3, 2, 3, 5, 4, 3, 3, 3, 2, 3

Offset: 2

Author

Reinhard Zumkeller, Jul 04 2005

Keywords

• nonn

Comments

a(n) = (A000040(n) - A109833(n)) / A109832(n).

Links

• Eric Weisstein's World of Mathematics, Prime Arithmetic Progression
• Index entries for sequences related to primes in arithmetic progressions