

A239474


Smallest k >= 1 such that k^nn is prime. a(n) = 0 if no such k exists.


1



3, 2, 2, 0, 4, 5, 60, 3, 2, 21, 28, 5, 2, 199, 28, 0, 234, 11, 2, 3, 2, 159, 10, 31, 68, 145, 0, 69, 186, 163, 32, 253, 26, 261, 4, 0, 8, 11, 62, 3, 22, 43, 6, 7, 8, 945, 76, 7, 116, 129, 382, 93, 330, 361, 2, 555, 224, 1359, 78, 29, 62, 39, 110, 0, 1032, 37, 462, 29
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OFFSET

1,1


COMMENTS

If n is of the form (pk)^p for some k and some prime p, then a(n) = 0 (See A097764).


LINKS

Table of n, a(n) for n=1..68.


FORMULA

a(A097764(n)) = 0 for all n.


EXAMPLE

1^11 = 0 is not prime. 2^11 = 1 is not prime. 3^11 = 2 is prime. Thus, a(1) = 3.


PROG

(Python)
import sympy
from sympy import isprime
def TwoMin(x):
..for k in range(1, 5000):
....if isprime(k**xx):
......return k
x = 1
while x < 100:
..print(TwoMin(x))
..x += 1


CROSSREFS

Cf. A072883, A028870, A153974, A239413, A239414, A239415, A239416, A239417, A239418.
Sequence in context: A178609 A144948 A108335 * A326152 A308181 A323557
Adjacent sequences: A239471 A239472 A239473 * A239475 A239476 A239477


KEYWORD

nonn


AUTHOR

Derek Orr, Mar 20 2014


STATUS

approved



