A308553 Numbers k such that 5^(k+3) + 3^(k+2) + 2^(k+1) + 1 is prime.

0, 4, 8, 524, 972, 3780, 7704

Offset: 1

Author

Mikk Heidemaa, Jun 07 2019

Keywords

• nonn
• hard
• more

Comments

Larger k values yield probable primes.

a(8) > 100000 (if it exists). - Michael S. Branicky, Nov 11 2024

Crossrefs

Cf. A306573.

Programs

Mathematica

ParallelTable[If[PrimeQ[5^(n+3) + 3^(n+2) + 2^(n+1) + 1], n, Nothing], {n, 0, 10^4}]