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A155941
Numbers n such that 16*n+1 is not prime.
3
0, 2, 3, 4, 5, 8, 9, 10, 11, 13, 14, 17, 18, 19, 20, 23, 24, 26, 29, 30, 31, 32, 33, 34, 35, 38, 39, 41, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 54, 56, 57, 59, 60, 62, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 77, 79, 80, 82, 83, 84, 86, 87, 89, 90, 91, 92, 94, 95
OFFSET
1,2
LINKS
EXAMPLE
Distribution of a(n)>0 in the following triangular array:
*;
*,*;
*,*,3;
*,*,*,5;
2,*,*,*,*;
*,4,*,*,*,*;
*,*,*,*,*,*,14;
*,*,*,*,*,*,*,18;
*,*,*,*,13,*,*,*,*;
*,*,*,*,*,17,*,*,*,*;
*,*,10,*,*,*,*,*,*,*,33;
*,*,*,14,*,*,*,*,*,*,*,39;
5,*,*,*,*,*,*,*,32,*,*,*,*; etc.
where * marks the non-integer values of (2*h*k + k + h)/8 with h >= k >= 1. - Vincenzo Librandi, Jan 15 2013
MATHEMATICA
Select[Range[0, 100], !PrimeQ[16 # + 1] &] (* Vincenzo Librandi, Oct 15 2012 *)
PROG
(Magma) [n: n in [0..100] |not IsPrime(16*n+1)]; // Vincenzo Librandi, Oct 15 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jan 31 2009
EXTENSIONS
0 added by Arkadiusz Wesolowski, Aug 03 2011
STATUS
approved