do loops - augmenting numbers

[112211]

I have attempted various methods, but I have been unable to obtain the desired output.

Using do loops 

I need output like following; 
1
121
12321
1234321
123454321

[Kurt_Bremser]

Please show us what you tried, so we can suggest ways to improve/correct your code.

[LinusH]

Is this some kind of training assignment?
The task doesn't reflect what you normally do using SAS...

[ballardw · Accepted solution]

Is the output one variable? Is it numeric or character? Maximum of 5 or how many rows? (Will severely limit whether the value is numeric or not

This makes a character value with that appearance.

data example;
   length var $ 25;
   do levels = 1 to 5;
      call missing(var);
      do j=1 to levels;
         var=cats(var,j);
      end;
      do j=(levels-1) to 1 by (-1);
         var=cats(var,j);
      end;
      output;
   end;
   drop levels j;
run;