OFFSET
1,1
COMMENTS
Also numbers k such that k concatenated with itself gives the product of two numbers which differ by 3.
EXAMPLE
7531357568//7531357564 = 8678339452 * 8678339457, where // denotes concatenation.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, Feb 06 2006
EXTENSIONS
Edited by N. J. A. Sloane, Apr 13 2007
STATUS
approved