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 A178500 #29 Jul 22 2025 01:11:45 %S A178500 0,10,100,1000,10000,100000,1000000,10000000,100000000,1000000000, %T A178500 10000000000,100000000000,1000000000000,10000000000000, %U A178500 100000000000000,1000000000000000,10000000000000000,100000000000000000,1000000000000000000,10000000000000000000,100000000000000000000 %N A178500 a(n) = 10^n * signum(n). %C A178500 a(n-1) is the minimum difference between an n-digit number (written in base 10, nonzero leading digit) and the product of its digits. For n > 1, it is also a number meeting that bound. See A070565. - _Devin Akman_, Apr 17 2019 %H A178500 Michael De Vlieger, <a href="/A178500/b178500.txt">Table of n, a(n) for n = 0..999</a> %H A178500 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (10). %F A178500 a(n) = A011557(n)*A057427(n). %F A178500 For n > 0, a(n) = A011557(n). %F A178500 a(n) = 10*A178501(n). %F A178500 a(n) = A000533(n) - 1. %F A178500 A061601(a(n)) = A109002(n+1). %F A178500 From _Elmo R. Oliveira_, Jul 21 2025: (Start) %F A178500 G.f.: 10*x/(1-10*x). %F A178500 E.g.f.: 2*exp(5*x)*sinh(5*x). %F A178500 a(n) = 10*a(n-1) for n > 1. (End) %t A178500 Array[10^#*Sign[#] &, 20, 0] (* _Michael De Vlieger_, Apr 21 2019 *) %Y A178500 Cf. A000533, A011557, A057427, A061601, A070565, A109002, A155559, A178501. %Y A178500 Partial sums of A063945. %K A178500 nonn,easy %O A178500 0,2 %A A178500 _Reinhard Zumkeller_, May 28 2010