login
a(n) is the minimum number whose product of digits contains n digits.
0

%I #13 Nov 19 2019 06:52:43

%S 1,25,269,2789,27999,289999,2999999,37999999,379999999,3899999999,

%T 39999999999,489999999999,4899999999999,49999999999999,

%U 589999999999999,5999999999999999,69999999999999999,699999999999999999,7999999999999999999,89999999999999999999,999999999999999999999,25999999999999999999999

%N a(n) is the minimum number whose product of digits contains n digits.

%C A007954(a(n)) is the first entry in A007954 to contain n digits, ignoring A007954(0).

%e a(2) = 25 as 2*5 = 10 which contains two digits, and no smaller value has a digit product with two digits.

%e a(4) = 2789 as 2*7*8*9 = 1008 which contains four digits, and no smaller value has a digit product with four digits.

%Y Cf. A007954.

%K nonn,base

%O 1,2

%A _Scott R. Shannon_, Nov 16 2019