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A344263
Numbers m such that 3^(2m+1) - 3^m + 1 is prime.
1
0, 3, 4, 11, 35, 56, 88, 104, 476, 1367, 1707, 2472, 22232, 25260
OFFSET
1,2
COMMENTS
a(14) > 30000.
a(14) > 50000. - Michael S. Branicky, Aug 12 2024
MAPLE
for m from 0 to 3000 do if isprime(3^(2*m + 1) - 3^m + 1) then print(m); end if; end do;
MATHEMATICA
Do[If[PrimeQ[3^(2 m + 1) - 3^m + 1], Print[m]], {m, 0, 3000}]
Select[Range[0, 2500], PrimeQ[3^(2#+1)-3^#+1]&] (* Harvey P. Dale, Mar 01 2023 *)
PROG
(PARI) for(m=0, 3e3, if(isprime(3^(2*m+1)-3^m+1), print1(m", ")))
(SageMath)
for m in range(3000):
if is_prime(3^(2*m + 1) - 3^m + 1):
print(m)
CROSSREFS
Cf. A344170.
Sequence in context: A084378 A038559 A242044 * A275309 A119042 A042273
KEYWORD
nonn,more
AUTHOR
Reza K Ghazi, May 13 2021
STATUS
approved