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A116169
Numbers k such that k concatenated with k+1 gives the product of two numbers which differ by 9.
8
9, 49, 1166975893986638437392162264780939, 1411174268292962563778302427727571, 1860631503683565562655236868895135
OFFSET
1,1
COMMENTS
Also numbers k such that k concatenated with k+9 gives the product of two numbers which differ by 7.
EXAMPLE
49//50 = 66 * 75, where // denotes concatenation.
49//58 = 67 * 74.
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, Feb 06 2006
EXTENSIONS
Edited by N. J. A. Sloane, Apr 15 2007
STATUS
approved