n = int(input())

prime = [True for _ in range(3 * n + 1)]
prime[0] = prime[1] = False
for x in range(2, 3 * n + 1):
  if not prime[x]:
    continue

  for y in range(2 * x, 3 * n + 1, x):
    prime[y] = False

cnt = [0 for _ in range(2 * n + 1)]
primes = []
ans = 0
for x in range(1, n + 1):
  if not prime[x]:
    continue

  if len(primes) < 1:
    primes.append(x)
    continue

  for s in range(x, 2 * primes[-1] + x + 1):
    if prime[s]:
      ans += cnt[s - x]

  for y in primes:
    cnt[x + y] += 1

  primes.append(x)

print("TEST")
print(ans)