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 A152278 #4 Jul 20 2015 03:51:08 %S A152278 0,2,31,336,3372,34973,356907,3612084,36476490,367550925,3697683123, %T A152278 37160602675,373149954035,3744652623110 %N A152278 Number of 6's among the digits of all n-digit primes. %Y A152278 Cf. A130817, A152272, A152273, A152274, A152275, A152276, A152277, A152279, A152280, A152281. %K A152278 base,nonn %O A152278 1,2 %A A152278 _Jon E. Schoenfield_, Dec 01 2008 %E A152278 a(12)-a(14) from _Giovanni Resta_, Jul 20 2015