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 A263470 #27 Feb 16 2025 08:33:27
%S A263470 0,24,476,6739,82401,902608,9394517,96122290,975700392,9854082822,
%T A263470 99180099587,995679223590,9977627937023,99879659224379,
%U A263470 999321444658475,9996118748668338,99978099721506172,999879067589400315,9999346524827012003,99996542810942397874
%N A263470 Total number of positive integers < 10^n with multiplicative digital root value 0.
%C A263470 Partial sums of A263476. - _Michel Marcus_, Oct 22 2015
%H A263470 Hiroaki Yamanouchi, <a href="/A263470/b263470.txt">Table of n, a(n) for n = 1..50</a>
%H A263470 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MultiplicativeDigitalRoot.html">Multiplicative Digital Root.</a>
%F A263470 a(n) + A000027(n) + A263471(n) + A000217(n) + A263472(n) + A263473(n) + A263474(n) + A000217(n) + A263475(n) + A000292(n) = A002283(n).
%t A263470 Length@ Select[Range[10^# - 1], FixedPoint[Times @@ IntegerDigits@ # &, #] == 0 &] & /@ Range@ 6 (* _Michael De Vlieger_, Oct 19 2015 *)
%o A263470 (PARI) t(k) = {while(k>9, k=prod(i=1, #k=digits(k), k[i])); k}
%o A263470 a(n) = sum(i=1, 10^n - 1, if(t(i) == 0, 1, 0)); \\ _Altug Alkan_, Oct 19 2015
%Y A263470 Cf. A031347, A034048, A263476.
%K A263470 nonn,base
%O A263470 1,2
%A A263470 _Martin Renner_, Oct 19 2015
%E A263470 a(9)-a(20) from _Hiroaki Yamanouchi_, Oct 25 2015