public void SmallestNumberThatCanBeDividedByNumbersUpTo20WithoutRemainder_Is232792560() { var divisors = Sequences.NumbersBetween(1, 21) .ToList(); var value = Sequences.NaturalNumbers() .Skip(1) //skip 0 .First(number => !divisors.Any(Conditional.HasRemainderWhenDividing(number))); Assert.AreEqual(232792560, value); }