from sys import argv

n = int(argv[1])
total = 3 * n ** 2

if n % 2 == 0:
  total += n

total += (n - 1) / 2 * n

def gcd(x, y):
  if y == 0:
    return x
  return gcd(y, x % y)

for i in xrange(1, n - 1):
  for j in xrange(i + 1, n + 1):
    d = gcd(i, j)
    i_ = i / d
    j_ = j / d
    total += min((n - i) / j_, j / i_) * 2
    total += min((n - j) / i_, i / j_) * 2


print total