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

1,1

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

Prog

(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

Crossrefs

Cf. A228323.

Sequence in context: A249350 A159082 A303576 * A171122 A342253 A296806

Adjacent sequences: A228321 A228322 A228323 * A228325 A228326 A228327

Keyword

nonn,base

Author

N. J. A. Sloane, Aug 20 2013

Extensions

More terms from Alois P. Heinz, Aug 20 2013

Status

approved