This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A231595 #12 Jun 16 2019 14:00:00
%S A231595 0,2,33,369,3741,38714,395621,4007705,40484195,408035120,4105718243,
%T A231595 41266320918,414416274953,4159068898063
%N A231595 Total number of 6's digits in primes less than 10^n.
%e A231595 a(2)=2, since there are 2 6's in primes less than 100. Namely: 61, 67.
%t A231595 Table[Count[IntegerDigits[Prime[Range[PrimePi[10^n - 1]]]], 6, 2], {n, 7}] (* _Robert Price_, Jun 16 2019 *)
%Y A231595 Cf. A231411, A231590-A231598, A119290, A119291-A119300.
%K A231595 more,nonn,base
%O A231595 1,2
%A A231595 _Robert Price_, Nov 11 2013
%E A231595 a(14) from _Giovanni Resta_, Jul 20 2015