OFFSET
1,2
COMMENTS
Also numbers k such that k concatenated with k+1 gives the product of two numbers which differ by 4.
Also numbers k such that k concatenated with k+4 gives the product of two numbers which differ by 2.
EXAMPLE
14564_14569 = 38163^2.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, Feb 06 2006
EXTENSIONS
Edited by N. J. A. Sloane, Apr 13 2007
STATUS
approved