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 A074461 #8 Jan 17 2020 03:29:23
%S A074461 2,3,5,7,1,2,4,5,2,5,2,5,2,3,5,4,7,3,6,4,5,8,5,8,8,0,1,2,3,1,3,1,3,4,
%T A074461 4,2,4,3,4,3,5,3,3,4,5,6,1,2,3,4,2,4,2,2,4,3,5,3,5,3,4,4,3,1,2,3,2,4,
%U A074461 4,5,3,5,5,4,6,4,6,6,1,4,4,2,2,3,5,3,5,5,3,4
%N A074461 Average digit (rounded down) in the decimal expansion of the n-th prime number.
%H A074461 Andrew Howroyd, <a href="/A074461/b074461.txt">Table of n, a(n) for n = 1..1000</a>
%F A074461 a(n) = A004426(A000040(n)). - _Reinhard Zumkeller_, May 27 2010
%e A074461 prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, ... so the average digits rounded down are; 2, 3, 5, 7, (1+1)/2 = 1, (1+3)/2 = 2, (1+7)/2 = 4, (1+9)/2 = 5, floor((2+3)/2) = 2, ...
%o A074461 (PARI) a(n)={my(v=digits(prime(n))); vecsum(v)\#v} \\ _Andrew Howroyd_, Jan 16 2020
%Y A074461 Cf. A000040, A004426, A074462.
%K A074461 easy,nonn,base
%O A074461 1,1
%A A074461 Y. Kelly Itakura (yitkr(AT)mta.ca), Aug 23 2002
%E A074461 Offset corrected and terms a(21) and beyond from _Andrew Howroyd_, Jan 16 2020