A241267 Numbers n such that 4*n^2 + 4*n + 653 is not prime.

18, 19, 21, 24, 28, 33, 39, 46, 54, 60, 61, 62, 63, 65, 67, 72, 73, 75, 81, 82, 84, 85, 86, 93, 95, 96, 100, 101, 103, 104, 105, 109, 110, 111, 112, 117, 121, 122, 123, 125, 130, 137, 138, 139, 141, 142, 143, 144, 147, 152, 153, 154, 159, 160, 161, 165, 166

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Example

19 is in this sequence because 4*19^2 + 4*19 + 653 = 2173 = 41*53.

Mathematica

Select[Range[0, 250], ! PrimeQ[4 #^2 + 4 # + 653] &]

Prog

(Magma) [n: n in [0..250] | not IsPrime(4*n^2+4*n+653)];

Crossrefs

Complement of A188459.

Sequence in context: A018823 A025144 A326540 * A241848 A146331 A308894

Adjacent sequences: A241264 A241265 A241266 * A241268 A241269 A241270

Keyword

nonn,easy

Author

Vincenzo Librandi, Apr 20 2014

Status

approved