A110775 Number of digits in A110774(n).

2, 1, 2, 2, 7, 10, 101, 196, 9, 550, 6150, 4532, 3249, 12360, 8719

Offset: 1

Author

Amarnath Murthy, Aug 12 2005

Keywords

• base
• nonn
• more

Crossrefs

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

Programs

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

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

a(14)-a(15) from Michael S. Branicky, Nov 19 2024