Thank you for answers of Juan, Mike and Vic.
Indeed [1:20].^2 works perfectly.
But is it possible to display [i,i^2] or [i,sqrt(i)] for [2:10] on line rather on a column ?
The message "undefined type ... " fortunately is not a crashing error, but I would know to declare the type of the variables that are the arguments of a function, in order to avoid the fastidious message "undefined ..".
I much appreciate the latest version of OCTAVE who can work on a Windows sceen rather a DOS screen.
Regards.