A336367 Numbers k such that gcd(k, prime(k) + prime(k+1)) > 1.

2, 3, 4, 6, 8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 26, 27, 28, 30, 32, 33, 34, 35, 36, 38, 40, 42, 44, 45, 46, 48, 50, 52, 54, 55, 56, 57, 58, 60, 62, 63, 64, 65, 66, 68, 69, 70, 72, 74, 75, 76, 78, 80, 81, 82, 84, 86, 87, 88, 90, 92, 93, 94, 96, 98, 100

Offset: 1

Author

Clark Kimberling, Oct 04 2020

Keywords

• nonn

Comments

Complement of A336366.

Examples

			In the following table, p(k) = A000040(k) = prime(k).
  k    p(k)   p(k)+p(k+1)   gcd
  1     2         5          1
  2     3         8          4
  3     5        12          3
  4     7        18          2
  5    11        24          1
  6    13        30          6
1 and 5 are in A336366; 2 and 3 are in this sequence; 2 and 11 are in A336368; 3 and 5 are in A336369.
		

Crossrefs

Cf. A000040, A336366, A336368, A336369.

Programs

Mathematica

p[n_] := Prime[n];
u = Select[Range[200], GCD[#, p[#] + p[# + 1]] == 1 &]  (* A336366 *)
v = Select[Range[200], GCD[#, p[#] + p[# + 1]] > 1 &]   (* A336367 *)
Prime[u] (* A336368 *)
Prime[v] (* A336369 *)