%I #8 Sep 19 2018 16:16:55

%S 26,44,59,61,79,86,103,106,109,125,128,131,146,149,151,161,163,166,

%T 169,179,184,187,194,205,224,236,239,254,257,265,266,268,271,274,278,

%U 281,289,293,296,304,313,316,326,334,341,346,350,355,359,364,367,376,389,391

%N Numbers n not divisible by 3 for which neither 2n-3 nor 2n+3 are primes.

%C This is A130699 with the trivial multiples of 3 removed.

%H Harvey P. Dale, <a href="/A130771/b130771.txt">Table of n, a(n) for n = 1..2500</a>

%e 26 because 2*26+3=55 is not a prime, nor is 2*26-3=49.

%t Select[Range[400],!Divisible[#,3]&&NoneTrue[2#+{3,-3},PrimeQ]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Sep 19 2018 *)

%o (PARI) isok(n) = (n % 3) && !isprime(2*n-3) && !isprime(2*n+3) \\ _Michel Marcus_, Jul 11 2013

%Y Cf. A130699, A001651.

%K easy,nonn

%O 1,1

%A _W. Neville Holmes_, Jul 14 2007

%E Missing term 169 added by _Michel Marcus_, Jul 11 2013