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Sum of k-digit multiples of n where k is the number of digits in n.
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%I #2 Dec 05 2013 19:57:00

%S 45,20,18,12,5,6,7,8,9,450,495,432,364,392,315,336,255,270,285,200,

%T 210,220,230,240,150,156,162,168,174,180,186,192,198,102,105,108,111,

%U 114,117,120,123,126,129,132

%N Sum of k-digit multiples of n where k is the number of digits in n.

%e a(12) = 12 +24 +...+84 +96= 432.

%K base,easy,nonn

%O 1,1

%A _Amarnath Murthy_, Jul 19 2005