A228324 Primes arising from A228323 in order of their appearance.

13, 23, 29, 59, 521, 421, 47, 67, 613, 1013, 1019, 1619, 1627, 827, 811, 1511, 1523, 1223, 1217, 2017, 2029, 1429, 1433, 2633, 2647, 1847, 1831, 2531, 2539, 2239, 2237, 2437, 2441, 3041, 3049, 3449, 3457, 2857, 2843, 3643, 3659, 3259, 3251, 3851, 3853, 4253

Offset: 1

Author

N. J. A. Sloane, Aug 20 2013

Keywords

• nonn
• base

References

• Eric Angelini, Posting to the Sequence Fans Mailing List, Aug 14 2013.

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..10000
• Index entries for primes involving decimal expansion of n

Crossrefs

Cf. A228323.

Programs

Python

from sympy import isprime
from itertools import islice
def c(s, t):
    u, v = int(s+t), int(t+s)
    if isprime(u): return u
    if isprime(v): return v
    return False
def agen():
    aset, k, mink = set(), 1, 2
    while True:
        an = k; aset.add(an); s, k = str(an), mink
        while k in aset or not c(s, str(k)): k += 1
        while mink in aset: mink += 1
        yield c(s, str(k))
print(list(islice(agen(), 46))) # Michael S. Branicky, Oct 17 2022

Extensions

More terms from Alois P. Heinz, Aug 20 2013