A205521 Numbers n such that 4*11^n - 1 is prime.

1, 3, 7, 13, 25, 243, 349, 3645, 10245, 40647, 40749

Offset: 1

Author

José María Grau Ribas, Jan 28 2012

Keywords

• nonn

Crossrefs

Cf. A199020 (4*11^n-1).

Cf. A120378 (numbers n such that 2*11^n - 1 is prime).

Cf. A046865 (numbers n such that 4*5^n - 1 is prime).

Cf. A005540 (numbers n such that 4*3^n - 1 is prime).

Programs

Mathematica

Table[If[PrimeQ[4*11^n-1],Print[n];n],{n,1,20000}]

PARI

is(n)=ispseudoprime(4*11^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(10)-a(11) from Dmitry Khomovsky, Aug 30 2017