A370659 Numbers k such that (4^k + 4*k)/4 is prime.

1, 3, 67, 247, 471, 1027, 6883, 11673

Offset

1,2

Comments

If it exists, a(9) > 75000.

Links

Table of n, a(n) for n=1..8.

Prog

(PARI) is(n) = ispseudoprime(4^(n-1)+n)

Crossrefs

Cf. A158879, A221906.

Sequence in context: A041983 A263549 A225191 * A201857 A294395 A342505

Adjacent sequences: A370656 A370657 A370658 * A370660 A370661 A370662

Keyword

nonn,hard,more

Author

Hugo Pfoertner, Feb 27 2024

Status

approved