1( 0 1 2 3 4 5 6 7 8 9 ) 2( 0 1 2 3 4 5 6 7 8 9 10 ) 3( 0 0 1 2 3 4 5 6 7 8 ) 4( 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 ) 5( 0 1 3 7 15 20 ) 6( 0 0 0 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 ) 7( 0 1 3 7 15 20 ) 8