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

1,6

Links

Table of n, a(n) for n=1..105.

Formula

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

Example

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

Crossrefs

Cf. A039995.

Different from A039996.

Sequence in context: A111709 A348911 A039996 * A348485 A343188 A326394

Adjacent sequences: A039991 A039992 A039993 * A039995 A039996 A039997

Keyword

nonn,base

Author

David W. Wilson

Extensions

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

Status

approved