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Number of primes embedded in decimal expansion of prime(n) as substrings.
2

%I #12 Jun 03 2024 18:09:34

%S 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,

%T 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,

%U 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

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

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

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

%Y Cf. A039995.

%Y Different from A039996.

%K nonn,base

%O 1,6

%A _David W. Wilson_

%E Definition and example clarified by _N. J. A. Sloane_, Jun 03 2024