The elements of the matrices are randomly generated.

Some tests:

n = 150  time = 4877  milliseconds
n = 140  time = 4132  milliseconds
n = 130  time = 3197  milliseconds
n = 120  time = 2513  milliseconds
n = 110  time = 1926  milliseconds
n = 100  time = 1612  milliseconds
n = 90   time = 1073  milliseconds
n = 80   time = 772   milliseconds
n = 70   time = 515   milliseconds
n = 60   time = 327   milliseconds
n = 50   time = 193   milliseconds
n = 40   time = 119   milliseconds
n = 30   time = 41    milliseconds
n = 20   time = 30    milliseconds
n = 10   time = 9     milliseconds

I can graphically represent the data (see the blue dots):

n: 0,10,20,30, 40, 50, 60, 70, 80,  90, 100, 110, 120, 130, 140, 150
t: 0, 9,30,41,119,193,327,515,772,1073,1612,1926,2513,3197,4132,4877

I sense that the trend could be quadratic. I check this by calculating the first and second differences (see).

The second differences oscillate around 0: I deduce that the trend is approximately quadratic.  I use quadratic regression (see):

I superimpose the graph on the points and I get the red curve in the previous diagram.