23 с двумя обязательными

a = [0] * 31
a[1] = 1
for i in range(2, 11):
    a[i] += a[i - 1]
    if i % 2 == 0:
        a[i] += a[i // 2]
for i in range(11, 22):
    a[i] += a[i - 1]
    if i % 2 == 0 and i // 2 >= 10:
        a[i] += a[i // 2]
for i in range(22, 31):
    a[i] += a[i - 1]
    if i % 2 == 0 and i // 2 >= 21:
        a[i] += a[i // 2]
print(a[30])