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 A263474 #23 Oct 25 2015 04:48:55
%S A263474 1,14,155,1172,6843,43538,318457,2223803,14185700,84670477,477808607,
%T A263474 2577052118,13759255632,75251167843,418157757456,2267313716636,
%U A263474 11616142299625,55909713312571,257522103127082,1182251998919171,5791219719115580,32715779086392723
%N A263474 Total number of positive integers < 10^n with multiplicative digital root value 6.
%C A263474 Partial sums of A263480.
%H A263474 Hiroaki Yamanouchi, <a href="/A263474/b263474.txt">Table of n, a(n) for n = 1..50</a>
%F A263474 A263470(n) + A000027(n) + A263471(n) + A000217(n) + A263472(n) + A263473(n) + a(n) + A000217(n) + A263475(n) + A000292(n) = A002283(n).
%t A263474 lim = 6; t = Select[Range[1, 10^lim - 1], FixedPoint[Times @@ IntegerDigits@ # &, #] == 6 &]; Count[t, n_ /; n <= 10^#] & /@ Range@ lim (* _Michael De Vlieger_, Oct 21 2015 *)
%o A263474 (PARI) t(k) = {while(k>9, k=prod(i=1, #k=digits(k), k[i])); k}
%o A263474 a(n) = sum(i=1, 10^n - 1, if(t(i) == 6, 1, 0)); \\ _Altug Alkan_, Oct 19 2015
%Y A263474 Cf. A031347, A034053, A263480.
%K A263474 nonn,base
%O A263474 1,2
%A A263474 _Martin Renner_, Oct 19 2015
%E A263474 a(9)-a(22) from _Hiroaki Yamanouchi_, Oct 25 2015