A057825 Values of k for which A003418(k) - 1 is prime.

3, 4, 5, 6, 7, 8, 19, 20, 21, 22, 23, 24, 29, 30, 32, 33, 34, 35, 36, 47, 48, 61, 62, 63, 97, 98, 99, 100, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 233, 234, 235, 236, 237, 238, 307, 308, 309, 310, 401, 402, 403, 404, 405, 406, 407, 408, 887, 888, 889, 890

Offset: 1

Author

Labos Elemer, Nov 08 2000

Keywords

• nonn

Comments

Fewer distinct primes than distinct values of a(n) are generated. So, e.g., k = 97, 98, 99, 100 all correspond to lcm([1..97]) - 1 = 69720375229712477164533808935312303556799, a prime.

Links

• Jinyuan Wang, Table of n, a(n) for n = 1..125

Crossrefs

Cf. A003418, A049536, A049537, A051451.

Programs

PARI

isok(k) = ispseudoprime(lcm(vector(k, i, i))-1); \\ Jinyuan Wang, May 02 2020