A110783 Number of digits in A110782(n).

2, 1, 3, 3, 2, 8, 21, 102, 25, 726, 954, 16522, 2939, 10691, 8157

Offset: 1

Author

Amarnath Murthy, Aug 12 2005

Keywords

• base
• nonn
• more

Comments

a(12) > 7300. - Michael S. Branicky, Aug 24 2022

Crossrefs

Cf. A110774, A110775, A110776, A110777, A110778, A110780, A110781, A110782.

Programs

Python

from sympy import isprime
from itertools import count, islice
def agen(): # generator of terms
    s = ""
    while True:
        for d in "1379":
            for k in count(1):
                if isprime(int(s+d*k)): break
            yield k
            s += d*k
print(list(islice(agen(), 11))) # Michael S. Branicky, Aug 24 2022

Extensions

More terms from Joshua Zucker, Jan 11 2006

a(11) from Sean A. Irvine, Mar 22 2010

a(12)-a(15) from Michael S. Branicky, Oct 14 2024