OFFSET
1,1
COMMENTS
Also, numbers k such that k concatenated with k+6 gives the product of two numbers which differ by 7.
EXAMPLE
4962//4960 = 7040 * 7049, where // denotes concatenation.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, Feb 06 2006
EXTENSIONS
Edited by N. J. A. Sloane at the suggestion of Eric Desbiaux, Mar 23 2008
STATUS
approved