C is the largest, and both sides are reduced at one time, so it is convenient to consider C.

C is at least 2. At this time, the situation is 1* 1= 1.

When c is 3, 3*3=9.

When c is 4, 6*6=36.

. . . . . .

When c is n, [n (n-1)/2] 2 = n 2 * (n-1) 2/4.

N is from 2 to 9. Although we found the recursive formula, we don't know this sum.

Forget it. . . . Precisely

1+9+36+ 100+225+44 1+784+ 1296=2892

I hope it helps you.