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A153464
Numbers k such that 4*k+9 is not prime.
1
0, 3, 4, 6, 9, 10, 12, 14, 15, 17, 18, 19, 21, 24, 27, 28, 29, 30, 31, 33, 34, 36, 38, 39, 40, 42, 44, 45, 48, 49, 50, 51, 52, 53, 54, 57, 59, 60, 61, 63, 64, 66, 69, 70, 72, 73, 74, 75, 78, 79, 80, 81, 83, 84, 87, 88, 89, 90, 92, 93, 94, 96, 99, 101, 102, 104, 105
OFFSET
1,2
LINKS
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
Cf. A111199.
Sequence in context: A080336 A082692 A032706 * A288463 A189297 A350977
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