A264011 Exponents n such that 2^(2*n+1) - 3*2^n - 1 (A195461) is prime.

2, 3, 4, 5, 8, 16, 27, 28, 33, 36, 48, 66, 90, 112, 508, 1036, 1041, 1560, 2208, 2668, 4388, 6097, 6517, 11353, 17284, 22385, 24740, 29805, 77188, 135219, 199237

Offset: 1

Author

Fabrice Lavier, Jan 03 2016

Keywords

• nonn
• more

Comments

Obtained using a Lucas-Lehmer-type test due to Williams.

Next term > 200000.

Links

• H. C. Williams, A class of primality tests for trinomials which includes the Lucas-Lehmer test, Pacific J. Math. Volume 98, Number 2 (1982), 477-494.

Crossrefs

Cf. A195461.

Programs

PARI

for(n=1,10^9,if(ispseudoprime(2^(2*n+1) - 3*2^n - 1),print1(n,", "))); \\ Joerg Arndt, Apr 08 2016