A153327 - OEIS

A153327

Numbers n such that 16*n+5 is not prime.

1, 4, 5, 7, 8, 10, 13, 15, 16, 19, 20, 21, 22, 25, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 39, 40, 43, 45, 46, 49, 50, 52, 54, 55, 56, 57, 58, 59, 60, 61, 64, 65, 67, 70, 71, 72, 73, 74, 75, 76, 78, 79, 80, 82, 83, 84, 85, 87, 88, 90, 91, 92, 94, 95, 96, 97, 98, 99, 100

(list; graph; refs; listen; history; text; internal format)

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,*,*;

*,*,*,*,10,*,*;

*,5,*,*,*,*,*,*;

*,*,8,*,*,*,*,*,*;

*,*,*,*,*,*,*,22,*,*;

4,*,*,*,*,*,*,*,27*,*;

*,*,*,*,*,20,*,*,*,*,*,*;

*,*,*,*,*,*,25,*,*,*,*,*,*; etc.

where * marks the non-integer values of (2*h*k + k + h - 2)/8 with h >= k >= 1. - Vincenzo Librandi, Jan 17 2013

MATHEMATICA

Select[Range[100], !PrimeQ[16# + 5]&] (* Harvey P. Dale, Oct 03 2011 *)

PROG

(Magma) [n: n in [0..150] | not IsPrime(16*n + 5)]; // Vincenzo Librandi, Jan 12 2013

CROSSREFS

Cf. A127590.

Sequence in context: A219115 A118731 A076203 * A189707 A120163 A088763

Adjacent sequences: A153324 A153325 A153326 * A153328 A153329 A153330

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Dec 23 2008

STATUS

approved