OFFSET
1,1
COMMENTS
Also numbers k such that k concatenated with k+9 gives the product of two numbers which differ by 6.
EXAMPLE
94090583//94090585 = 97000297 * 97000305, where // denotes concatenation.
94090583//94090592 = 97000298 * 97000304.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, Feb 06 2006
EXTENSIONS
Edited by N. J. A. Sloane, Apr 13 2007
STATUS
approved