OFFSET
1,1
COMMENTS
Every term is a multiple of 3.
Numbers k such that 100*k+11 and 100*k+13 are prime. - Chai Wah Wu, Jan 20 2022
EXAMPLE
311, 2111, 2711, 7211, and 9011 are terms of A001359.
MAPLE
terms := proc(n)
local k, p, L:
k, L := 0, []:
while numelems(L) < n do
k := k+1:
p := parse(cat(k, 11)):
if isprime(p) and isprime(p+2) then L := [op(L), k]: fi: od:
L: end:
MATHEMATICA
Select[Range[1282], AllTrue[# + {0, 2}, PrimeQ] &[100 # + 11] &] (* Michael De Vlieger, Dec 21 2021 *)
PROG
(Python)
from itertools import count, islice
from sympy import isprime
def A350247_gen(startvalue=3): # generator of terms >= startvalue
for n in count(max(3, startvalue+(3-startvalue%3)%3), 3):
if isprime(100*n+11) and isprime(100*n+13):
yield n
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Lorenzo Sauras Altuzarra, Dec 21 2021
STATUS
approved