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 A085708 #17 Mar 17 2024 19:47:17
%S A085708 0,7,140,2100,28000,350000,4200000,49000000,560000000,6300000000,
%T A085708 70000000000,770000000000,8400000000000,91000000000000,
%U A085708 980000000000000,10500000000000000,112000000000000000,1190000000000000000,12600000000000000000,133000000000000000000
%N A085708 Arithmetic derivative of 10^n.
%C A085708 a(n) = A003415(A011557(n)) = A008589(n)*A011557(n-1).
%H A085708 Vincenzo Librandi, <a href="/A085708/b085708.txt">Table of n, a(n) for n = 0..100</a>
%H A085708 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (20,-100).
%F A085708 a(n) = 7*n*10^(n-1).
%F A085708 G.f.: 7*x/(10*x-1)^2.
%t A085708 Table[7*n*10^(n-1),{n,0,20}] (* _Harvey P. Dale_, Jul 09 2021 *)
%o A085708 (Magma) [7*n*10^(n-1): n in [0..20]]; // _Vincenzo Librandi_, Jun 09 2011
%Y A085708 Cf. A001787, A003415, A008589, A011557, A027471.
%K A085708 nonn,easy
%O A085708 0,2
%A A085708 _Reinhard Zumkeller_, Jul 19 2003