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a(n) = 10^n * signum(n).
7

%I #25 Feb 06 2024 01:57:29

%S 0,10,100,1000,10000,100000,1000000,10000000,100000000,1000000000,

%T 10000000000,100000000000,1000000000000,10000000000000,

%U 100000000000000,1000000000000000,10000000000000000,100000000000000000

%N a(n) = 10^n * signum(n).

%C 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 Michael De Vlieger, <a href="/A178500/b178500.txt">Table of n, a(n) for n = 0..999</a>

%H <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (10).

%F a(n) = A011557(n) * A057427(n).

%F For n > 0, a(n) = A011557(n).

%F a(n) = 10 * A178501(n).

%F a(n) = A000533(n) - 1.

%F A061601(a(n)) = A109002(n+1).

%t Array[10^#*Sign[#] &, 20, 0] (* _Michael De Vlieger_, Apr 21 2019 *)

%Y Cf. A000533, A011557, A057427, A061601, A070565, A109002, A155559, A178501.

%Y Partial sums of A063945.

%K nonn,easy

%O 0,2

%A _Reinhard Zumkeller_, May 28 2010