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 A061546 #4 May 10 2013 12:44:46
%S A061546 7,77,777,7777,77777,777777,3999999,4688999,4689899,4689989,4689998,
%T A061546 4698899,4698989,4698998,4699889,4699898,4699988,4868999,4869899,
%U A061546 4869989,4869998,4886999,4888888,4889699,4889969,4889996,4896899
%N A061546 Harmonic mean of digits is 7.
%e A061546 6666999 is a term since 7/(1/6+1/6+1/6+1/6+1/9+1/9+1/9)=7.
%t A061546 Do[ h = IntegerDigits[n]; If[ Sort[h][[1]] != 0 && Length[h]/Apply[Plus, 1/h] == 7, Print[n]], {n, 1, 10^6}]
%Y A061546 Cf. A062179-A062185, A061383-A061388, A061423-A061425.
%K A061546 base,easy,nonn
%O A061546 1,1
%A A061546 _Vladeta Jovovic_, Jun 13 2001
%E A061546 More terms from _Robert G. Wilson v_, Aug 08 2001