1 polyominos of size 1
*

1 polyominos of size 2
*
*

2 polyominos of size 3
*   
* * 
* **

5 polyominos of size 4
*            
* *  *      *
* *  ** ** **
* ** *  ** * 

12 polyominos of size 5
*                                       
* *  *                 *                
* *  *  *  ** *   *   **  *   **   *  * 
* *  ** ** *  *   *** *  *** **  *** ***
* ** *  ** ** *** *   *  *   *   *    * 

6 polyominos of size 6
*                      
*  *    *            * 
** *    *   *   *    * 
*  *** *** *** **** ***
*  *   *   * * *     * 

5 polyominos of size 7
*                      
*    *   *    *        
***  *   *    *     *  
*   *** **** **** *****
*   * * *     *     *  

1 polyominos of size 8
  *  
  *  
*****
  *  

1 polyominos of size 9
  *  
  *  
*****
  *  
  *  

0 polyominos of size 10
Total 3-indecomposible polyominos = 34
Size >= 3 3-indecomposible polyominos = 32
Size >= 6 3-indecomposible polyominos = 13