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A270104 Numbers n such that 3^n + n*2^n is prime. 1
1, 2, 7, 8, 13, 43, 55, 59, 145, 149, 545, 2468, 4049, 4055, 15653, 22765 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(17) > 30000. - Giovanni Resta, May 05 2016

LINKS

Table of n, a(n) for n=1..16.

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

Cf. A270102, A123924.

Sequence in context: A004717 A308918 A226819 * A063531 A063771 A064293

Adjacent sequences:  A270101 A270102 A270103 * A270105 A270106 A270107

KEYWORD

nonn,more

AUTHOR

Vardan Semerjyan, Mar 11 2016

EXTENSIONS

a(15)-a(16) from Giovanni Resta, May 05 2016

STATUS

approved

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Last modified May 18 10:28 EDT 2022. Contains 353807 sequences. (Running on oeis4.)