bash -----9*9

[root@python ~]# vim 9*9.sh

#!/bin/bash 
for ((i=1;i<=9;i++));do
  for ((j=1;j<=i;j++));do
    if ( [ $j -eq 2 ] && [ $(($i*$j)) -eq 6 ] ) || ( [ $j -eq 2 ] && [ $(($i*$j)) -eq 8 ] )
    then  echo -n "${i}x$j=$(($i*$j))  "
    else  echo -n "${i}x$j=$(($i*$j)) "
    fi
  done
     echo
done
~     

[root@python py]# bash  9*9.sh
1x1=1 
2x1=2 2x2=4 
3x1=3 3x2=6  3x3=9 
4x1=4 4x2=8  4x3=12 4x4=16 
5x1=5 5x2=10 5x3=15 5x4=20 5x5=25 
6x1=6 6x2=12 6x3=18 6x4=24 6x5=30 6x6=36 
7x1=7 7x2=14 7x3=21 7x4=28 7x5=35 7x6=42 7x7=49 
8x1=8 8x2=16 8x3=24 8x4=32 8x5=40 8x6=48 8x7=56 8x8=64 
9x1=9 9x2=18 9x3=27 9x4=36 9x5=45 9x6=54 9x7=63 9x8=72 9x9=81