N = int(input())
A = list(map(int, input().split()))

cnt = 0
for i in range(N-1, -1, -1):
    if A[i] > i+1 or (A[i] + cnt) % (i+1) != 0:
        print('No')
        exit()
    if A[i] > 0:
        cnt += 1
print('Yes')