A110777 - OEIS

%I #20 Nov 21 2024 02:18:54

%S 2,3,2,6,9,25,9,3,762,354,248,2181,606,1941,6423,11871

%N Number of digits in A110776(n).

%o (Python)

%o from sympy import isprime

%o from itertools import count, islice

%o def agen(): # generator of terms

%o     s = ""

%o     while True:

%o         for d in "17":

%o             for k in count(1):

%o                 if isprime(int(s+d*k)): break

%o             yield k

%o             s += d*k

%o print(list(islice(agen(), 11))) # _Michael S. Branicky_, Aug 23 2022

%Y Cf. A110774, A110775, A110776, A110778, A112534, A110780, A110781, A110782, A110783, A110788, A110789

%K base,nonn,more

%O 1,1

%A _Amarnath Murthy_, Aug 12 2005

%E a(7)-a(9) from _Joshua Zucker_, Jan 11 2006

%E a(10)-a(11) from _Sean A. Irvine_, Mar 22 2010

%E a(12)-a(14) from _Michael S. Branicky_, Aug 23 2022

%E a(15) from _Michael S. Branicky_, May 29 2023

%E a(16) from _Michael S. Branicky_, Nov 20 2024