A049848 a(n) is the number of primes q less than n-th prime p for which the Euclidean algorithm for p,q has exactly 2 nonzero remainders.

0, 0, 1, 1, 1, 2, 4, 3, 2, 3, 2, 4, 6, 5, 3, 2, 5, 3, 5, 5, 5, 6, 3, 6, 6, 7, 5, 5, 6, 5, 7, 4, 7, 5, 8, 4, 8, 6, 5, 4, 4, 7, 6, 6, 8, 7, 7, 9, 10, 7, 6, 4, 9, 7, 8, 9, 7, 7, 6, 8, 4, 4, 10, 6, 7, 9, 7, 7, 8, 5, 11, 4, 9, 10, 10, 6, 9, 7, 12, 12, 9, 9, 7, 12

Offset

1,6

Links

Table of n, a(n) for n=1..84.

Example

For prime(6)=13, the primes counted are 7 and 11.

Crossrefs

Cf. A049849, A049850.

Sequence in context: A238847 A011030 A005681 * A152026 A345928 A060806

Adjacent sequences: A049845 A049846 A049847 * A049849 A049850 A049851

Keyword

nonn

Author

Clark Kimberling

Extensions

More terms from Sean A. Irvine, Aug 07 2021

Status

approved