A053584 a(n+1) is the smallest prime ending with a(n), where a(1)=7.

7, 17, 317, 6317, 26317, 126317, 2126317, 72126317, 372126317, 5372126317, 125372126317, 15125372126317, 415125372126317, 23415125372126317, 2223415125372126317, 152223415125372126317, 21152223415125372126317, 4221152223415125372126317

Offset: 1

Author

G. L. Honaker, Jr., Jan 18 2000

Keywords

• base
• nonn

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..372

Crossrefs

Cf. A000040, A053582, A053583, A069612.

Programs

Python

from sympy import isprime
from itertools import count, islice
def agen(an=7):
    while True:
        yield an
        pow10 = 10**len(str(an))
        for t in count(pow10+an, step=pow10):
            if isprime(t):
                an = t
                break
print(list(islice(agen(), 18))) # Michael S. Branicky, Jun 23 2022