OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[Range[8, 200], !PrimeQ[2*#-7]&] (* Vladimir Joseph Stephan Orlovsky, Feb 09 2012 *)
PROG
(Magma) [n: n in [5..220]| not IsPrime(2*n-7)]
(PARI) list(n)=apply(k->(k+7)/2, setminus(vector(n, k, 2*k+7), primes(primepi(2*n+7)))) \\ Charles R Greathouse IV, May 14 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Dec 17 2008
EXTENSIONS
Partially edited by N. J. A. Sloane, Jun 23 2010
STATUS
approved