A155941 Numbers n such that 16*n+1 is not prime.

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

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

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

Cf. A094407, A155942, A155943.

Sequence in context: A031482 A047369 A004827 * A046892 A068406 A276878

Adjacent sequences: A155938 A155939 A155940 * A155942 A155943 A155944

Keyword

nonn,easy

Author

Vincenzo Librandi, Jan 31 2009

Extensions

0 added by Arkadiusz Wesolowski, Aug 03 2011

Status

approved