OFFSET
1,3
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
FORMULA
Complement of A000043.
EXAMPLE
8 belongs to the sequence because 2^8 - 1 = 255 is not a prime.
MATHEMATICA
Select[Range[0, 100], !PrimeQ[2^#-1]&] (* Harvey P. Dale, Mar 22 2011 *)
PROG
(Magma) [n: n in [0..100]| not IsPrime(2^n-1)]; // Vincenzo Librandi, Jan 28 2011
CROSSREFS
KEYWORD
nonn,easy,nice,changed
AUTHOR
EXTENSIONS
More terms from Jennifer D. Secor (s1175994(AT)cedarville.edu)
STATUS
approved