

A096819


Exponents k such that 2^k  19 is prime.


12



5, 7, 11, 15, 19, 21, 31, 39, 67, 69, 85, 157, 171, 191, 255, 291, 379, 3669, 4551, 9531, 13119, 14211, 20647, 233965, 337267, 534429, 535415, 816039, 991715
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OFFSET

1,1


COMMENTS

All terms are odd since for even k, 2^k  19 is divisible by 3.


LINKS



EXAMPLE

2^7  19 = 128  19 = 109, a prime, so 7 is a term of the sequence.


MATHEMATICA



CROSSREFS

Exponents for primes of 2^kd form: A000043 (d=1), A050414 (d=3), A059608 (d=5), A059609 (d=7), A059610 (d=9), A096817 (d=11), A096818 (d=13), A059612 (d=15), A059611 (d=17), A096819 (d=19), A096820 (d=21).


KEYWORD

nonn,more


AUTHOR



EXTENSIONS

a(24)a(25) from Lelio R Paula, added by Max Alekseyev, Oct 24 2013
a(26)a(29) found by Stefano Morozzi, added by Alois P. Heinz, Aug 29 2022


STATUS

approved



