%I #23 Mar 21 2022 03:07:19

%S 6,53550,420420,422310,1624350,2130240,3399900,5199810,5246010,

%T 6549270,7384440,7775880,9516570,9565710,10430280,11845260,13207950,

%U 14562870,14619990,18747960,20099940,21596820,21968100,24358950,24610740,26916120,28359240,30838080

%N Numbers k such that k-1, k+1, 2*k-1, 2*k+1, 3*k-1 and 3*k+1 are primes.

%e 6 is there because 5, 7, 11, 13, 17, 19 are all prime.

%t Select[Range[25*10^6],AllTrue[Flatten[{#+{1,-1},2#+{1,-1},3#+{1,-1}}], PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Sep 13 2016 *)

%Y Cf. A014574, A066388, A118860, A349321, A348348.

%K nonn

%O 1,1

%A _Labos Elemer_, May 03 2006

%E Edited by _Don Reble_, May 16 2006

%E a(26)-a(28) from _Jon E. Schoenfield_, Dec 07 2021