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Product of all k-digit numbers starting from n where k is the number of digits in n. a(n) = n*(n+1)*...*(10^k-1), where k is the number of digits in n.
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%I #8 Aug 09 2015 00:47:32

%S 362880,362880,181440,60480,15120,3024,504,72,9

%N Product of all k-digit numbers starting from n where k is the number of digits in n. a(n) = n*(n+1)*...*(10^k-1), where k is the number of digits in n.

%C The subsequent terms are too large to include: a(10) has 151 digits, a(11) has 150 digits, a(12) has 149 digits. - _R. J. Mathar_, Feb 08 2008

%p A110452 := proc(n) local k ; k := nops(convert(n,base,10)) ; mul(i,i=n..10^k-1) ; end: for n from 1 to 13 do printf("%d, ",A110452(n)) ; od: # _R. J. Mathar_, Feb 08 2008

%K base,nonn

%O 1,1

%A _Amarnath Murthy_, Aug 04 2005