OFFSET
1,3
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..9000
EXAMPLE
4 is in the sequence because (4^2+2)/3 = 2*3.
MATHEMATICA
Select[Range[0, 200], ! PrimeQ[(#^2 + 2)/3] &]
PROG
(Magma) [0, 1, 3] cat [ n: n in [2..90] | not IsPrime((n^2+2) div 3) ];
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Apr 21 2014
STATUS
approved