A344263 Numbers m such that 3^(2m+1) - 3^m + 1 is prime.

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

Links

Table of n, a(n) for n=1..14.

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

Adjacent sequences: A344260 A344261 A344262 * A344264 A344265 A344266

Keyword

nonn,more

Author

Reza K Ghazi, May 13 2021

Status

approved