A109066 Number of prime digits in n-th prime.

1, 1, 1, 1, 0, 1, 1, 0, 2, 1, 1, 2, 0, 1, 1, 2, 1, 0, 1, 1, 2, 1, 1, 0, 1, 0, 1, 1, 0, 1, 2, 1, 2, 1, 0, 1, 2, 1, 1, 2, 1, 0, 0, 1, 1, 0, 1, 3, 3, 2, 3, 2, 1, 2, 3, 2, 1, 2, 3, 1, 2, 2, 2, 1, 2, 2, 2, 3, 2, 1, 3, 2, 2, 3, 2, 2, 1, 2, 0, 0, 0, 1, 1, 2, 1, 1, 0, 2, 0, 1, 1, 1, 1, 0, 0, 2, 1, 2, 3, 1, 2, 3, 2, 1, 2

Offset: 1

Author

Zak Seidov, Jun 17 2005

Keywords

• base
• nonn

Comments

The prime A000040(n) is in A034844 iff a(n) = 0; it is in A179336 iff a(n) > 0. [Reinhard Zumkeller, Jul 11 2010, corrected by M. F. Hasler, Aug 27 2012]

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A019546 (primes whose digits are primes), A092629 (number of prime digits is nonprime), A104250 (sum of prime digits of n-th prime).

Cf. A000040, A034844, A179336.

Programs

Mathematica

a[n_]:=Count[PrimeQ/@IntegerDigits[Prime[n]], True]

PARI

a(n) = vecsum(apply(x->isprime(x), digits(prime(n)))); \\ Michel Marcus, Mar 15 2019

Formula

a(n) = A193238(A000040(n)). [Reinhard Zumkeller, Jul 19 2011]