OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
EXAMPLE
Distribution of the terms in the following triangular array:
*;
*,*;
*,*,*;
*,*,*,*;
*,4,*,*,*;
*,*,7,*,*,*;
*,*,*,*,*,*,*;
*,*,*,*,15,*,*,*;
*,*,*,*,*,20,*,*,*;
*,*,*,*,*,*,*,*,*,*;
*,9,*,*,*,*,*,32,*,*,*;
*,*,14,*,*,*,*,*,39,*,*,*; etc.
where * marks the non-integer values of (2*h*k + k + h - 3)/6 with h >= k >= 1. - Vincenzo Librandi, Jan 14 2013
MATHEMATICA
Select[Range[0, 200], !PrimeQ[12 # + 7] &] (* Vincenzo Librandi, Jan 14 2013 *)
PROG
(Magma) [n: n in [0..150] | not IsPrime(12*n+7)]; // Vincenzo Librandi, Jan 14 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Oct 29 2009
STATUS
approved