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A178500
a(n) = 10^n * signum(n).
7
0, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000, 10000000000, 100000000000, 1000000000000, 10000000000000, 100000000000000, 1000000000000000, 10000000000000000, 100000000000000000
OFFSET
0,2
COMMENTS
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
FORMULA
a(n) = A011557(n) * A057427(n).
For n > 0, a(n) = A011557(n).
a(n) = 10 * A178501(n).
a(n) = A000533(n) - 1.
A061601(a(n)) = A109002(n+1).
MATHEMATICA
Array[10^#*Sign[#] &, 20, 0] (* Michael De Vlieger, Apr 21 2019 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Reinhard Zumkeller, May 28 2010
STATUS
approved