A365958 Least k such that 8*n*k+1 is a prime.

2, 1, 3, 3, 1, 2, 2, 3, 1, 3, 1, 1, 3, 1, 2, 2, 1, 3, 3, 4, 2, 2, 7, 1, 2, 6, 2, 2, 1, 1, 6, 1, 5, 5, 1, 2, 2, 4, 1, 2, 7, 1, 3, 1, 5, 9, 3, 2, 8, 1, 1, 3, 4, 1, 2, 1, 1, 2, 4, 7, 2, 3, 2, 15, 1, 4, 3, 10, 3, 5, 1, 1, 3, 1, 1, 2, 1, 2, 6, 1, 2, 12, 3, 1, 2

Offset

1,1

Links

Robert Price, Table of n, a(n) for n = 1..5000

Mathematica

A365958 = {};
Do[k=1; While[!PrimeQ[8 n k+1], k++]; AppendTo[A365958 , k], {n, 85}];
A365958

Prog

(PARI) a(n) = my(k=1); while (!isprime(8*n*k+1), k++); k; \\ Michel Marcus, Dec 17 2023

Crossrefs

Cf. A016014, A005123.

A070852 lists the corresponding primes.

Sequence in context: A245554 A110569 A140815 * A351963 A134840 A352356

Adjacent sequences: A365955 A365956 A365957 * A365959 A365960 A365961

Keyword

nonn

Author

Robert Price, Dec 17 2023

Status

approved