A108473 - OEIS

%I #5 Feb 18 2013 15:09:25

%S 3,4,5,6,7,8,9,10,11,12,13,14,17,19,20,21,22,24,25,26,27,28,29,30,31,

%T 33,34,35,37,38,39,40,41,42,43,44,45,46,47,48,49,50,52,53,54,57,59,60,

%U 61,62,63,64,65,66,67,68,69,70,71,72,73,75,76,77,78,79,80,81,82,83,84,85

%N Numbers n such that 4*prime(n)+prime(n+1) is composite.

%C Complement to A108472.

%t ra=Range[200];cnd=!PrimeQ[4*Prime[ # ]+Prime[ #+1]]&;se=Select[ra, cnd]

%t Rest[Flatten[Position[4First[#]+Last[#]&/@Partition[Prime[Range[100]],2,1],_?(!PrimeQ[#]&)]]] (* _Harvey P. Dale_, Feb 18 2013 *)

%Y Cf. A108472.

%K nonn

%O 1,1

%A _Zak Seidov_, Jun 04 2005