Implementation of the "Sieve of Eratosthenes" algorithm for generating prime numbers up to N in C#

SieveOfEratosthenes.cs

/// <summary>
/// Implementation of the "Sieve of Eratosthenes" algorithm for generating prime numbers up to N in C#
/// </summary>
public static class SieveOfEratosthenes {

    /// <summary>
    /// Checking for a prime number with <see cref="Sieve(int)"/>
    /// </summary>
    /// <param name="num">Number to check</param>
    /// <returns>Is <paramref name="num"/> prime number or not</returns>
    public static bool IsPrimeNumber(int num) => Sieve(num).Contains(num);

    /// <summary>
    /// Generates an array of prime numbers up to <paramref name="generateTo"/> 
    /// </summary>
    /// <param name="generateTo">Array limit</param>
    /// <returns>An array of prime integers</returns>
    public static int[] Sieve(int generateTo) {
        List<int> output = new();
        bool[] checks = new bool[++generateTo];
        Array.Fill(checks, true);
        checks[0] = checks[1] = false;
        for (int i = 0; i < checks.Length; i++) {
            if (!checks[i]) continue;
            for (int j = 2; j <= checks.Length; j++) {
                if (i * j >= checks.Length) break;
                checks[i * j] = false;
            }
        }
        for (int i = 0; i < checks.Length; i++) if (checks[i]) output.Add(i);
        return output.ToArray();
    }
}