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A270104
Numbers k such that 3^k + k*2^k is prime.
1
1, 2, 7, 8, 13, 43, 55, 59, 145, 149, 545, 2468, 4049, 4055, 15653, 22765, 99932
OFFSET
1,2
COMMENTS
a(17) > 30000. - Giovanni Resta, May 05 2016
EXAMPLE
n = 2 is a term since 3^2 + 2*2^2 = 17 is prime.
MATHEMATICA
Select[Range[1000], PrimeQ[3^# + # * 2^#]&] (* Giovanni Resta, May 05 2016 *)
PROG
(MATLAB)
if isprime(3^n + n*2^n)
disp(n)
end
(PARI) is(n)=ispseudoprime(3^n+n*2^n) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Sequence in context: A004717 A308918 A226819 * A063531 A063771 A064293
KEYWORD
nonn,more
AUTHOR
Vardan Semerjyan, Mar 11 2016
EXTENSIONS
a(15)-a(16) from Giovanni Resta, May 05 2016
a(17) from Michael S. Branicky, Jul 06 2024
STATUS
approved