m = 2
s = 2
F_K = [[1, 2], [3, 4]]
F = [[2, 1], [4, 3]]

a = [[F] + [np.zeros((m, m))] * s] + \
[[F] + [np.zeros((m, m))] * i + [F_K] + [np.zeros((m, m))] * (s-i-1) for i in range(0, s)]

for i in range(m):
    a = np.hstack(a)

print(a.reshape((m*(s+1), m*(s+1))))