OFFSET
1,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
EXAMPLE
Distribution of the terms in the following triangular array:
0;
*,4;
3,*,10;
*,9,*,18;
6,*,17,*,28;
*,14,*,27,*,40;
9,*,24,*,39,*,54;
*,19,*,36,*,53,*,70;
12,*,31,*,50,*,69,*,88;
*,24,*,45,*,66,*,87,*,108;
15,*,38,*,61,*,84,*,107,*,130; etc.
where * marks the non-integer values of (2*h*k + k + h - 4)/2 with h >= k >= 1. - Vincenzo Librandi, Jan 14 2013
MATHEMATICA
Select[Range[0, 200], !PrimeQ[4 # + 9] &] (* Vincenzo Librandi, Jan 14 2013 *)
PROG
(Magma) [n: n in [0..150] | not IsPrime(4*n+9)]; // Vincenzo Librandi, Jan 14 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Dec 27 2008
EXTENSIONS
79 added by R. J. Mathar, Sep 23 2009
0 added by Arkadiusz Wesolowski, Aug 03 2011
STATUS
approved