OFFSET
1,2
EXAMPLE
The greatest product of two numbers using digits 0 through 7,for instance, occurs when the difference between them is least (since X*Y={(X+Y)^2 - (X-Y)^2}/4), i.e., when the product equals 7420*6531=48640020=a(7).
CROSSREFS
KEYWORD
fini,full,nonn,base
AUTHOR
Lekraj Beedassy, Feb 01 2007
EXTENSIONS
Edited by Charles R Greathouse IV, Aug 05 2010
STATUS
approved