For example to only select a number that is larger than the previous one. I don't currently know of any LINQ method that would allow me to do such a thing

Actually there is a LINQ extension which allows you to do that. the Where extension has an overload that uses the item value and the item's index:

return collection.Where((x, i) => (i > 0)?x > collection[i - 1]:false);

For example to only select a number that is larger than the previous one. I don't currently know of any LINQ method that would allow me to do such a thing

Actually there is a LINQ extension which allows you to do that. the Where extension has an overload that uses the item value and the item's index:

List<int> test1 = new List<int>()
{
    23,
    45,
    16,
    8,
    90,
    25
};
var test2 = test1.Where((x, i) => (i > 0)?x > test1[i - 1]:false);

One caveat to this is, it will only work for indexed collections of types that support comparison operators.