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 A263472 #25 Oct 25 2015 04:49:52
%S A263472 1,10,65,279,894,2345,6174,66354,1005399,9737884,66699415,356586629,
%T A263472 1585685916,6342292785,30560724590,264486626166,2926013859615,
%U A263472 28611339267816,232062904906327,1588966488941437,9421788721876388,49444241961339027,233673191793220620
%N A263472 Total number of positive integers < 10^n with multiplicative digital root value 4.
%C A263472 Partial sums of A263478.
%H A263472 Hiroaki Yamanouchi, <a href="/A263472/b263472.txt">Table of n, a(n) for n = 1..50</a>
%F A263472 A263470(n) + A000027(n) + A263471(n) + A000217(n) + a(n) + A263473(n) + A263474(n) + A000217(n) + A263475(n) + A000292(n) = A002283(n).
%t A263472 lim = 6; t = Select[Range[1, 10^lim - 1], FixedPoint[Times @@ IntegerDigits@ # &, #] == 4 &]; Count[t, n_ /; n <= 10^#] & /@ Range@ lim (* _Michael De Vlieger_, Oct 21 2015 *)
%o A263472 (PARI) t(k) = {while(k>9, k=prod(i=1, #k=digits(k), k[i])); k}
%o A263472 a(n) = sum(i=1, 10^n - 1, if(t(i) == 4, 1, 0)); \\ _Altug Alkan_, Oct 19 2015
%Y A263472 Cf. A031347, A034051, A263478.
%K A263472 nonn,base
%O A263472 1,2
%A A263472 _Martin Renner_, Oct 19 2015
%E A263472 a(9)-a(23) from _Hiroaki Yamanouchi_, Oct 25 2015