A039994 Number of primes embedded in decimal expansion of prime(n) as substrings.

1, 1, 1, 1, 1, 2, 2, 1, 3, 2, 2, 3, 1, 2, 2, 3, 2, 1, 2, 2, 3, 2, 2, 1, 2, 2, 3, 3, 2, 4, 4, 5, 6, 4, 2, 3, 4, 3, 4, 6, 5, 2, 3, 4, 5, 2, 3, 4, 3, 3, 4, 5, 3, 3, 4, 4, 3, 4, 3, 2, 5, 5, 4, 4, 4, 6, 3, 4, 5, 2, 4, 4, 5, 5, 5, 3, 3, 5, 2, 1, 3, 3, 5, 3, 3, 3, 1, 4, 3, 3, 4, 4, 3, 2, 1, 4, 3, 3, 6, 3, 4, 3, 4, 3, 4

Offset: 1

Author

David W. Wilson

Keywords

• nonn
• base

Examples

			a(26) = 2 since prime(26) = 101 and "101" has two prime subsequences, 101 and 11.
		

Crossrefs

Cf. A039995.

Different from A039996.

Formula

a(n) = A039995(prime(n)).

Extensions

Definition and example clarified by N. J. A. Sloane, Jun 03 2024