login
A241267
Numbers n such that 4*n^2 + 4*n + 653 is not prime.
1
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
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
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Apr 20 2014
STATUS
approved