20.01.2022

#1
def f(n):
    if n == 1:
        return 1
    elif n > 1 and n % 2 == 0:
        return 2 * f(n-1)
    elif n > 1 and n % 2 == 1:
        return 5 * n + f(n-2)

print(f(64))

#2
def g(n):
    if n == 1:
        return 1
    else:
        return f(n-1) + 3 * g(n-1) - 3*n

def f(n):
    if n == 1:
        return 1
    else:
        return 3 * f(n-1) + g(n-1) - n + 5

print(f(14) + f(14))

#3
def f(n):
    if n > 25:
        return 2 * n * n * n + 1
    else:
        return f(n + 2) + 2 * f(n + 3)

cnt = 0
for n in range(1, 1001):
    if f(n) % 11 == 0:
        cnt += 1
print(cnt)

#4
def f(n):
    if n > 30:
        return n * n + 5 * n + 4
    elif n <= 30 and n % 2 == 0:
        return f(n+1) + 3 * f(n+4)
    elif n <= 30 and n % 2 == 1:
        return 2 * f(n+2) + f(n+5)

cnt = 0
for n in range(1, 1001):
    s = list(str(f(n)))
    cnt2 = 0
    for i in s:
        cnt2 += int(i)
    if cnt2 == 27:
        cnt += 1
print(cnt)