OFFSET
1,2
COMMENTS
FORMULA
a(n) = A089161(n)+1.
EXAMPLE
1 is a term because 1*30 - 13 = 17 = prime(6) and 1*30 - 11 = 19 = prime(7).
4 is a term because 4*30 - 13 = 107 = prime(28) and 4*30 - 11 = 109 = prime(29).
5 is a term because 5*30 - 13 = 137 = prime(33) and 5*30 - 11 = 139 = prime(34).
MATHEMATICA
Select[Range[300], And @@ PrimeQ[30*# - {11, 13}] &] (* Amiram Eldar, Feb 29 2020 *)
PROG
(Rexx)
S = 1
do N = 2 while length( S ) < 255
if NOPRIME( N*30 -13 ) then iterate N
if NOPRIME( N*30 -11 ) then iterate N
S = S || ', ' N
end N
say S
(PARI) isok(k) = isprime(30*k-13) && isprime(30*k-11); \\ Michel Marcus, Feb 29 2020
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Frank Ellermann, Feb 26 2020
STATUS
approved