A301632 Numbers k such that 3^k + k + 1 is a prime.
0, 1, 3, 15, 45, 117, 159, 3739, 3777, 9703, 10623, 21459, 86595
Offset: 1
Programs
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Maple
a:=n->`if`(isprime(3^k+k+1),k,NULL): seq(a(k),k=0..6000); # Muniru A Asiru, Mar 25 2018
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Mathematica
Flatten[{0, Select[Range[5000], PrimeQ[3^# + # + 1] &]}] (* Vaclav Kotesovec, Mar 25 2018 *) -
PARI
for(n=0, 1000, if(isprime(3^n+n+1), print1(n", ")))
Extensions
a(8)-a(9) from Muniru A Asiru, Mar 25 2018
a(10)-a(11) from Vaclav Kotesovec, Mar 25 2018
a(12) from Altug Alkan, Apr 01 2018
a(13) from Giovanni Resta, Apr 06 2018
Comments