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URL: https://oeis.org/A301632

⇱ A301632 - OEIS

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A301632
Numbers k such that 3^k + k + 1 is a prime.
3
0, 1, 3, 15, 45, 117, 159, 3739, 3777, 9703, 10623, 21459, 86595
OFFSET
1,3
COMMENTS
a(14) > 200000. - Michael S. Branicky, May 19 2025
MAPLE
a:=n->`if`(isprime(3^k+k+1), k, NULL): seq(a(k), k=0..6000); # Muniru A Asiru, Mar 25 2018
MATHEMATICA
Flatten[{0, Select[Range[5000], PrimeQ[3^# + # + 1] &]}] (* Vaclav Kotesovec, Mar 25 2018 *)
PROG
(PARI) for(n=0, 1000, if(isprime(3^n+n+1), print1(n", ")))
CROSSREFS
A182327 gives the primes.
Sequence in context: A050534 A048099 A030505 * A074355 A201868 A260021
KEYWORD
nonn,more,hard
AUTHOR
Seiichi Manyama, Mar 25 2018
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
STATUS
approved