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 A069709 #11 Apr 28 2023 19:56:35
%S A069709 2,3,5,7,11,13,17,19,31,37,53,59,71,73,79,97,1021,1061,1069,1087,1151,
%T A069709 1201,1223,1249,1289,1429,1447,1483,1487,1511,1559,1601,1609,1627,
%U A069709 1663,1667,1753,1847,1861,1933,1951,1973,1999,2011,2099,2141,2213,2239,2293
%N A069709 Primes with arithmetic mean of digits an integer (sum of digits = a multiple of number of digits).
%H A069709 Delbert L. Johnson, <a href="/A069709/b069709.txt">Table of n, a(n) for n = 1..20000</a>
%t A069709 Do[p = Prime[n]; If[ IntegerQ[ Apply[ Plus, IntegerDigits[p]] / Floor[ Log[10, p] + 1]], Print[p]], {n, 1, 10^3}]
%t A069709 Select[Prime[Range[400]],IntegerQ[Mean[IntegerDigits[#]]]&] (* _Harvey P. Dale_, Jan 29 2012 *)
%Y A069709 Cf. A069710, A069711, A069712.
%K A069709 nonn,base
%O A069709 1,1
%A A069709 _Amarnath Murthy_, Apr 08 2002
%E A069709 Edited and extended by _Robert G. Wilson v_, Apr 12 2002