A145315 - OEIS

%I #11 Nov 08 2022 16:46:43

%S 1,43,3772,86022,691263,1940280,2445785,2539018,3355288,4492167,

%T 4598112,5517709,5731956,7466941,8409234,9817872,10324700,10390862,

%U 12138468,13631232,17181592,17382707,17609073,20633677,20897582,22760333,23389302,32968102,36051016,37215088

%N Numbers k for which the set {30*k-13, 30*k-11, 30*k-7, 30*k-1, 30*k+1, 30*k+7, 30*k+11, 30*k+13} forms a symmetrical prime octuplet.

%C a(n) is always +/- 1 (mod 7).

%F a(n) = (A022012(n) + 13)/30. - _Hugo Pfoertner_, Nov 08 2022

%t spoQ[n_]:=Module[{c=30n},And@@PrimeQ[{c-13,c-11,c-7,c-1,c+1,c+7,c+11, c+13}]]; Select[Range[23000000],spoQ] (* _Harvey P. Dale_, Oct 10 2011 *)

%Y Cf. A022012.

%K nonn

%O 1,2

%A _Andrey V. Kulsha_, Oct 07 2008