A087865 Prime numbers of the form primepi(3^m), for some integer m.

2, 53, 16097, 120739, 334349, 18703411700669

Offset

1,1

Comments

These are the prime terms in A055729.

Links

Table of n, a(n) for n=1..6.

Mathematica

Select[ Table[ PrimePi[ 3^n], {n, 0, 49}], PrimeQ@# &] (* Robert G. Wilson v, Feb 25 2010 *)

Prog

(PARI) primeslessxn2(n, p) = /*primes < p^n if prime */ { sr=0; for(x=0, n, y=primepi(p^x); if(y<>0, sr+=1.0/y); if(isprime(y), print1(y", ")); ); print(); print(sr) }

Crossrefs

Cf. A055729 (number of primes <= 3^n).

Sequence in context: A176946 A265443 A234603 * A278843 A083471 A078691

Adjacent sequences: A087862 A087863 A087864 * A087866 A087867 A087868

Keyword

nonn,more,hard

Author

Cino Hilliard, Oct 27 2003

Extensions

a(6) added by David Baugh, Mar 17 2015

Status

approved