OFFSET
1,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
EXAMPLE
Distribution of the positive terms in the following triangular array:
*;
*,*;
*,*,*;
*,*,*,*;
*,3,*,*,*;
*,*,5,*,*,*;
*,*,*,*,*,*,*;
*,*,*,*,*,*,*,16;
*,*,*,*,*,*,*,*,20;
*,*,*,*,*,*,*,*,*,*;
*,*,*,*,14,*,*,*,*,*,*; etc.
where * marks the noninteger values of (2*h*k + k + h)/9 with h >= k >= 1. - Vincenzo Librandi, Jan 14 2013
MATHEMATICA
Select[Range[0, 200], !PrimeQ[18 # + 1] &] (* Vincenzo Librandi, Jan 14 2013 *)
PROG
(Magma) [n: n in [0..150] | not IsPrime(18*n+1)]; // Vincenzo Librandi, Jan 14 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Dec 25 2008
EXTENSIONS
0 added by Arkadiusz Wesolowski, Aug 03 2011
STATUS
approved