/// <summary>
///
/// </summary>
public AdditiveRecurrence(int a, int b, int c, int d)
{
var x = (a + b * ContinuedFraction.Sqrt(c, 60)) / d;
var g = BigInteger.Pow(2, 64);
var y = Rational.Floor(Rational.Frac(x.Convergents().Last()) * g);
if (y == g)
{
y--;
}
value = 0;
increment = (ulong)y | 1UL;
}
