

A155935


Numbers n such that 13*n + 5 is not prime.


1



1, 3, 4, 5, 7, 9, 10, 11, 12, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 59, 60, 61, 63, 64, 65, 67, 68, 69, 70, 71, 73, 75, 76, 77, 79, 80, 81
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OFFSET

1,2


LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000


EXAMPLE

Distribution of the even terms in the following triangular array::
*;
*,*;
*,*,*;
*,*,*,*;
*,*,*,*,*;
*,*,*,*,*,*;
*,*,*,10,*,*,*;
*,*,*,*,14,*,*,*;
4,*,*,*,*,*,*,*,*;
*,*,*,*,*,*,*,*,*,*;
*,*,12,*,*,*,*,*,*,*,*;
*,*,*,*,*,*,*,*,*,40,*,*; etc.
where * marks the noninteger values of (4*h*k + 2*k + 2*h  4)/13 with h >= k >= 1.  Vincenzo Librandi, Jan 15 2013


MATHEMATICA

Select[Range[0, 100], !PrimeQ[13 # + 5] &] (* Vincenzo Librandi, Oct 15 2012 *)


PROG

(MAGMA) [n: n in [0..90]  not IsPrime(13*n + 5)];


CROSSREFS

Cf. A102732, A154610.
Sequence in context: A112882 A180152 A162610 * A081606 A079945 A283736
Adjacent sequences: A155932 A155933 A155934 * A155936 A155937 A155938


KEYWORD

nonn,easy


AUTHOR

Vincenzo Librandi, Jan 31 2009


STATUS

approved



