xorcubes001.cpp

#include <stdio.h>
#include <inttypes.h>
#include <assert.h>

typedef uint32_t uint_t;
const uint32_t N = 1 << 11, P = 998244353;

static uint32_t cubes[N];

int main()
{
    for (uint64_t i = 0; i < N; i++) {
        cubes[i] = (i * i % P) * i % P;
    }

    uint32_t n = 0;
    int st = scanf("%u", &n);
    assert (st == 1);
    assert (n < N);
    n++;

    uint64_t res = 0;
    for (uint32_t i = 0; i < n; i++) {
        for (uint32_t j = 0; j < i; j++) {
            uint64_t rk = 0;
            for (uint32_t k = 0; k < j; k++) {
                rk +=  cubes[i ^ k] * (uint64_t) cubes[j ^ k];
                if (k % 16 == 15)
                    rk %= P;
            }
            res = (res + rk % P * cubes[i ^ j]) % P;
        }
    }
    res = res * 6 % P;
    printf("%u\n", (uint32_t) res);

}