A391798 - OEIS

%I #10 Jan 01 2026 23:31:00

%S 2,3,5,11,13,14,15,17,19,21,22,32,36,39,41,47,52,53,63,74,75,76,77,83,

%T 86,88,91,93,96,106,118,122,124,125,128,136,137,143,151,157,173,174,

%U 175,195,199,217,219,237,238,242,259,261,280,289,290,293,296

%N Numbers k such that prime(2*k + 2) - prime(2*k) = prime(2*k + 1) - prime(2*k - 1).

%t z = 300; p[n_] := Prime[n];

%t a[n_] := p[2 n + 2] - p[2 n] - p[2 n + 1] + p[2 n - 1];

%t Select[Range[z], a[#] < 0 &]   (* A391797 *)

%t Select[Range[z], a[#] == 0 &]  (* A391798 *)

%t Select[Range[z], a[#] > 0 &]   (* A391799 *)

%Y Cf. A000027, A000040, A022884, A110854, A391797, A391799, A391800.

%K nonn

%O 1,1

%A _Clark Kimberling_, Dec 23 2025