

A249305


Primes n such that 2^n  n^2 is not squarefree.


0




OFFSET

1,1


COMMENTS

Sequence is infinite, containing all primes equal to 2, 4, 89, or 115 mod 147.  Charles R Greathouse IV, Oct 28 2014


LINKS

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


FORMULA

a(n) < (21 + e)n log n for any e > 0 and all large enough n.  Charles R Greathouse IV, Oct 28 2014


EXAMPLE

2 is in this sequence because 2 is prime and 2^2  2^2 = 0 is not squarefree.


PROG

(MAGMA) [n: n in [3..269]  IsPrime(n) and not IsSquarefree(2^n  n^2)];
(PARI) is(n)=isprime(n) && !issquarefree(2^nn^2) \\ Charles R Greathouse IV, Oct 28 2014


CROSSREFS

Cf. A005117, A024012.
Sequence in context: A139881 A161676 A235467 * A023302 A041967 A226768
Adjacent sequences: A249302 A249303 A249304 * A249306 A249307 A249308


KEYWORD

nonn,more


AUTHOR

JuriStepan Gerasimov, Oct 25 2014


EXTENSIONS

a(5)a(6) from Charles R Greathouse IV, Oct 28 2014


STATUS

approved



