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%I #20 Jun 24 2023 06:34:57
%S 2,5,9,10,38,47,1279,11389
%N Number of digits in A110780(n).
%C a(8) > 8000. - _Michael S. Branicky_, Aug 24 2022
%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 "19":
%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(), 7))) # _Michael S. Branicky_, Aug 24 2022
%Y Cf. A110774, A110775, A110776, A110777, A110778, A110780.
%K base,nonn,more
%O 1,1
%A _Amarnath Murthy_, Aug 12 2005
%E More terms from _Joshua Zucker_, Jan 11 2006
%E a(7) from _Sean A. Irvine_, Mar 22 2010
%E a(8) from _Michael S. Branicky_, Jun 24 2023
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