A243292 Odd numbers n such that (4^n - 1)/3 is a base-2 pseudoprime.

5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 85, 89, 91, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271

Offset: 1

Author

Arkadiusz Wesolowski, Jun 02 2014

Keywords

• nonn

Comments

Odd numbers not divisible by 3 that are primes or pseudoprimes to base 4.

Links

• Wikipedia, Fermat pseudoprime
• Index entries for sequences related to pseudoprimes

Crossrefs

Cf. A000040, A001567, A020136, A210454.

Programs

Magma

[n: n in [1..271 by 2] | not n mod 3 eq 0 and IsOne(4^(n-1) mod n)];