A132830 Numbers of the form 3^n+2 which are not primes.

245, 731, 2189, 19685, 177149, 531443, 1594325, 43046723, 129140165, 387420491, 1162261469, 3486784403, 10460353205, 31381059611, 94143178829, 847288609445, 7625597484989, 22876792454963, 68630377364885, 205891132094651

Offset: 1

Author

Artur Jasinski, Sep 03 2007

Keywords

• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A057735, A051783, A132829.

Programs

Mathematica

a = {}; c = 3^x + 2; Do[If[PrimeQ[c],0, AppendTo[a, c]], {x, 0, 100}]; a (*Artur Jasinski*)
Select[3^Range[0,30]+2,!PrimeQ[#]&] (* Harvey P. Dale, Nov 21 2012 *)