|
|
A153044
|
|
Numbers n such that 2*n-9 is not a prime.
|
|
3
|
|
|
5, 9, 12, 15, 17, 18, 21, 22, 24, 27, 29, 30, 32, 33, 36, 37, 39, 42, 43, 45, 47, 48, 50, 51, 52, 54, 57, 60, 62, 63, 64, 65, 66, 67, 69, 71, 72, 75, 76, 77, 78, 81, 82, 84, 85, 87, 89, 90, 92, 93, 96, 97, 98, 99, 102, 105, 106, 107, 108, 109, 111, 112, 113, 114, 115, 117, 120
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
The terms after a(1) are the values of 2*h*k + k + h + 5, where h and k are positive integers. - Vincenzo Librandi, Jan 19 2013
|
|
LINKS
|
|
|
MATHEMATICA
|
|
|
PROG
|
(Magma) [n: n in [5..121] | not IsPrime(2*n-9)]; // Bruno Berselli, Mar 05 2011
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|