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:
*;
1,*;
*,*,*;
*,*,7,*;
*,6,*,*,*;
4,*,*,*,17,*;
*,*,*,16,*,*,*;
*,*,14,*,*,*,31,*;
*,11,*,*,*,30,*,*,*;
7,*,*,*,28,*,*,*,49,*:
*,*,*,25,*,*,*,48,*,*,*;
*,*,21,*,*,*,46,*,*,*,71,*; etc.
where * marks the non-integer values of (2*h*k + k + h - 3)/4 with h >= k >= 1. - Vincenzo Librandi, Jan 15 2013
MATHEMATICA
Select[Range[0, 200], !PrimeQ[8 # + 7] &] (* Vincenzo Librandi, Jan 12 2013 *)
PROG
(Magma) [n: n in [0..110] | not IsPrime(8*n+7)]; // Vincenzo Librandi, Jan 12 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Dec 21 2008
STATUS
approved