A095906 Numbers n such that 3^n-2^(n-1) is prime.

1, 2, 3, 4, 5, 9, 10, 11, 12, 16, 29, 34, 41, 61, 73, 186, 191, 241, 282, 1075, 1404, 1991, 2116, 3399, 3935, 4924, 5353, 7660, 8645, 11832, 16029, 17370, 19182, 22386, 27295, 30570, 41125, 61498, 64786, 72820, 90221, 122506, 132570, 142249, 179489, 181378

Offset: 1

Author

Herman H. Rosenfeld (herm3(AT)pacbell.net) and Robert G. Wilson v, Jun 17 2004

Keywords

• nonn
• more

Comments

a(47) > 2*10^5. - Robert Price, Jan 14 2016

Crossrefs

Cf. A082103.

Programs

Mathematica

Do[ If[ PrimeQ[3^n - 2^(n - 1)], Print[n]], {n, 3000}]

PARI

is(n)=ispseudoprime(3^n-2^(n-1)) \\ Charles R Greathouse IV, Jun 05 2017

Extensions

More terms from Ray G. Opao, Jul 22 2004

a(30)-a(46) from Robert Price, Jan 14 2016