A354694 Least Euler pseudoprime to base 2 through base prime(n).

341, 1729, 1729, 46657, 46657, 162401, 399001, 399001, 399001, 399001, 488881, 3057601, 3057601, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 3828001, 17098369, 17098369, 17098369, 17098369, 17236801, 17236801

Offset: 1

Author

Jinyuan Wang, Jun 04 2022

Keywords

• nonn

Comments

a(n) is coprime to A002110(n).

Links

• Eric Weisstein's World of Mathematics, Euler Pseudoprime.

Crossrefs

Cf. A002110, A007324, A083876, A271221.

Programs

PARI

a(n) = my(b, m, p=factorback(primes(n))); forcomposite(k=9, oo, if(gcd(k, p)==1, b=2; while((m=Mod(b, k)^(k\2)) == 1 || m == k-1, b++); if(b>prime(n), return(k))));