Lambert summation

Imagine you have a lot of numbers, let's say from 1 to 10. Now, you want to add all these numbers up, but it takes a lot of time to do it one by one. Lambert summation is a trick that helps you add up all these numbers quickly.

So, to do Lambert summation, you group the numbers together in pairs. In our example, you would group 1+10, 2+9, 3+8, 4+7, and 5+6. Then you add up each of these pairs to get 11, 11, 11, 11, and 11. That gives you a total of 55.

But, what if you have an odd number of numbers? Say, you have 1 to 6. You can still use Lambert summation, but you would just leave out the middle number, which in this case is 3. So, you would group 1+6, 2+5, and 4+6 (notice that we skip 3). This gives you 7, 7, and 10. Add those together and you get 24.

Lambert summation can help you add up a lot of numbers quickly, especially when there are many of them. It's like making a puzzle and then solving it to get the answer, but a much faster way of doing it!