A110775 Number of digits in A110774(n).

2, 1, 2, 2, 7, 10, 101, 196, 9, 550, 6150, 4532, 3249

Offset

1,1

Links

Table of n, a(n) for n=1..13.

Prog

(Python)
from sympy import isprime
from itertools import count, islice
def agen(): # generator of terms
    s = ""
    while True:
        for d in "13":
            for k in count(1):
                if isprime(int(s+d*k)): break
            yield k
            s += d*k
print(list(islice(agen(), 10))) # Michael S. Branicky, Aug 23 2022

Crossrefs

Cf. A110774, A110776, A110777, A110778, A112534, A110780, A110781, A110782, A110783, A110788, A110789

Sequence in context: A145859 A145863 A240492 * A229232 A092186 A138262

Adjacent sequences: A110772 A110773 A110774 * A110776 A110777 A110778

Keyword

base,nonn,more

Author

Amarnath Murthy, Aug 12 2005

Extensions

Corrected and extended by Joshua Zucker, Jan 11 2006

a(11) from Michael S. Branicky, Aug 23 2022

a(12)-a(13) from Michael S. Branicky, May 29 2023

Status

approved