for (int n : NEGATIVE_INTEGER_CANDIDATES) {
      assertThrows(IllegalArgumentException.class, () -> IntMath.factorial(n));
    }
  }

  // Depends on the correctness of BigIntegerMath.binomial.
  public void testBinomial() {
    for (int n = 0; n <= 50; n++) {
      for (int k = 0; k <= n; k++) {
        BigInteger expectedBig = BigIntegerMath.binomial(n, k);

    for (int n : NEGATIVE_INTEGER_CANDIDATES) {
      assertThrows(IllegalArgumentException.class, () -> LongMath.factorial(n));
    }
  }

  // Depends on the correctness of BigIntegerMath.binomial.
  public void testBinomial() {
    for (int n = 0; n <= 70; n++) {
      for (int k = 0; k <= n; k++) {
        BigInteger expectedBig = BigIntegerMath.binomial(n, k);