N = int(input())
used = [0] * (N+1)
sq = []
for i in range(1, N+1):
    if i*i > N:
        break
    used[i*i] = 1
    sq.append(i*i)

ans = len(sq) ** 2
for x in range(1, N+1):
    if used[x]:
        continue

    cnt = 0
    for y in sq:
        if x * y > N:
            break
        if used[x * y]:
            continue
        used[x * y] = 1
        cnt += 1
    ans += cnt * cnt
print(ans)