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 A152275 #7 Jul 20 2015 03:48:26
%S A152275 1,8,66,602,5552,52541,505880,4907822,47923752,469985783,4625005356,
%T A152275 45629711436,451086676886,4466423651321
%N A152275 Number of 3's among the digits of all n-digit primes.
%t A152275 Join[{1},Table[Count[Flatten[IntegerDigits/@Prime[Range[PrimePi[10^(n-1)]+ 1,PrimePi[10^n]]]],3],{n,2,11}]] (* _Harvey P. Dale_, Dec 18 2011 *)
%Y A152275 Cf. A130817, A152272, A152273, A152274, A152276, A152277, A152278, A152279, A152280, A152281.
%K A152275 base,nonn
%O A152275 1,2
%A A152275 _Jon E. Schoenfield_, Dec 01 2008
%E A152275 a(12)-a(14) from _Giovanni Resta_, Jul 20 2015