OFFSET
1,2
COMMENTS
Numbers k for which three of 10*k-3, 10*k-1, 10*k+1, 10*k+3 are prime.
Note: they can't all be prime because at least one must be divisible by 3.
No terms are divisible by 3.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
filter:= n -> nops(select(isprime, [10*n-3, 10*n-1, 10*n+1, 10*n+3]))=3:
select(filter, [$1..1000]); # Robert Israel, Nov 22 2018
MATHEMATICA
Select[Range[1204], AllTrue[Rest@Sort@PrimeQ[10 # + {-3, -1, 1, 3}], TrueQ] &] (* Amiram Eldar, Nov 22 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert Israel, Nov 22 2018
STATUS
approved