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 A152273 #4 Jul 20 2015 03:46:37 %S A152273 0,9,69,603,5672,53281,510523,4940488,48169672,471970959,4641157883, %T A152273 45764403814,452221586920,4476140736522 %N A152273 Number of 1's among the digits of all n-digit primes. %Y A152273 Cf. A130817, A152272, A152274, A152275, A152276, A152277, A152278, A152279, A152280, A152281. %K A152273 base,nonn %O A152273 1,2 %A A152273 _Jon E. Schoenfield_, Dec 01 2008 %E A152273 a(12)-a(14) from _Giovanni Resta_, Jul 20 2015