OFFSET
1,1
COMMENTS
Complement of A147820. - Omar E. Pol, Nov 17 2008
m is in the sequence iff A177961(m)<m. - Vladimir Shevelev, May 16 2010
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
EXAMPLE
a(1)=13 is the first number satisfying simultaneously the two rules.
MATHEMATICA
Select[ Range[300], !PrimeQ[2# + 1] && !PrimeQ[2# - 1] &] (* Robert G. Wilson v, Apr 18 2005 *)
Select[Range[300], NoneTrue[2#+{1, -1}, PrimeQ]&] (* The program uses the NoneTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jul 07 2015 *)
PROG
(Haskell)
a104278 n = a104278_list !! (n-1)
a104278_list = [m | m <- [1..],
a010051' (2 * m - 1) == 0 && a010051' (2 * m + 1) == 0]
-- Reinhard Zumkeller, Aug 04 2015
(PARI) select( {is_A104278(n)=!isprime(2*n-1)&&!isprime(2*n+1)}, [1..222]) \\ M. F. Hasler, Apr 29 2024
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Alexandre Wajnberg, Apr 17 2005
EXTENSIONS
More terms from Robert G. Wilson v, Apr 18 2005
STATUS
approved