OFFSET
1,1
COMMENTS
There are 18 digit pairs which can produce such primes. (1,0),(1,3),(1,4),(1,6),(1,7),(1,9),(2,3),(2,9),(3,4),(3,5),(3,7),(3,8),(4,7),(4,9),(5,9),(6,7),(7,9),(8,9).
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..10000
PROG
(Python)
from sympy import isprime
from sympy.utilities.iterables import multiset_permutations
def auptodigs(maxdigits):
alst = []
for d in range(2, maxdigits + 1, 2):
ms = "2"*(d//2) + "3"*(d//2 - 1)
for p in multiset_permutations(ms, d-1):
t = int("".join(p) + "3")
if isprime(t):
alst.append(t)
return alst
print(auptodigs(10)) # Michael S. Branicky, Jan 11 2022
(PARI) \\ Needs B() from A087510.
concat(vector(6, k, B(k, 2, 3, isprime))) \\ Andrew Howroyd, Sep 21 2024
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Paul D. Hanna and Amarnath Murthy, Sep 12 2003
EXTENSIONS
Offset changed to 1 and a(19) corrected by Georg Fischer, Jan 11 2022
STATUS
approved