%I #14 Apr 09 2020 19:17:14
%S 0,2,7,8,10,11,13,14,16,17,19,20,22,24,25,27,28,29,31,32,33,35,36,38,
%T 40,41,43,44,46,48,49,51,52,54,55,57,58,59,61,62,63,65,66,68,70,71,73,
%U 74,75,77,78,80,82,84,85,87,88,90,91,95,96,98,100,101,103,104,106,107,109
%N Numbers n such that exactly one of n+-1 and n+-2 is prime.
%H Harvey P. Dale, <a href="/A168064/b168064.txt">Table of n, a(n) for n = 1..1000</a>
%e a(1)=0 (-2,-1 and 1 are nonprime, 2 is prime); a(2)=2 (0,1 and 4 are nonprime, 3 is prime); a(3)=7 (6,8 and 9 are nonprime, 5 is prime); a(4)=10 (8,9 and 12 are nonprime, 11 is prime); a(5)=11 (9,10 and 12 are nonprime, 13 is prime).
%t Join[{0},Select[Range[120],Total[Boole[PrimeQ[#+{-2,-1,1,2}]]]==1&]] (* _Harvey P. Dale_, Apr 09 2020 *)
%o (PARI) is(n)=isprime(n-2)+isprime(n-1)+isprime(n+1)+isprime(n+2)==1 \\ _Charles R Greathouse IV_, Jun 13 2017
%Y Cf. A000040, A100317, A141468.
%K nonn,easy
%O 1,2
%A _Juri-Stepan Gerasimov_, Nov 18 2009