Consider how Strassen's algorithm divides an n×n matrix into smaller submatrices when n is not a power of 2 (like 7×7).

Recall that Strassen's original method uses 7 multiplications for 2×2 matrices, but the number may change for larger or non-power-of-2 matrices due to padding or recursive splitting.

Generalize the recurrence relation for the number of multiplications in Strassen's algorithm for an n×n matrix, where n is not necessarily a power of 2, and solve for n = 7.