Power sum MASTER CLASS: How to sum quadrillions of powers ... by hand! (Euler-Maclaurin formula)
Why Mathematics Stack Exchange recommends it
Mathematics Stack Exchange users link it when someone asks about sums of powers, Faulhaber's formula, Bernoulli numbers, or visual and geometric proofs of sum-of-squares style identities.
Recommended by 5 people across 7 different months, 2019 to 2023.
What it is
A 50-minute Mathologer video that builds up formulas for power sums (1^k + 2^k + ... + n^k) from scratch, with animated proofs without words, Bernoulli numbers and Faulhaber's formula. It ends with an accessible introduction to the Euler-Maclaurin summation formula.
What people said
Strong rec K.defaoite · 2020-07 · Mathematics Stack Exchange · on “Sum of Squares $i^2$”
Not super rigorous, but this amazing animation [this video] is a nice visual proof. In fact watch the entire video, it's fantastic.
Strong rec K.defaoite · 2021-04 · Mathematics Stack Exchange · on “Induction on $S(n,k)$”
This is a well known problem in mathematics. See Faulhaber's formula [LINK] and this excellent Mathologer video [this video] .
Recommends Toby Mak · 2019-11 · Mathematics Stack Exchange · on “Can you go from the integral of x squared to the summation of x squared?”
Mathologer [this video] did a whole episode on your topic. Although the derivation does not use calculus, it is still quite useful to what you are asking. Your part starts at 9:28.
Recommends Jonah · 2020-03 · Mathematics Stack Exchange · on “Geometric interpretation for sum of fourth powers”
This mathologer video [this video] is not exactly an answer to your question, but goes into the general formula for any power in an accessible, visual way.
Recommends K.defaoite · 2020-05 · Mathematics Stack Exchange · on “Simple proof by induction problems”
Also, I'm not sure induction is the best method for your other problem. Learning about integer power sums, which Mathologer has a great video [this video] on would help you with this problem.
Recommends Antoni Parellada · 2023-05 · Mathematics Stack Exchange · on “What is the simple dependence of the diagonals (or columns) of the Faulhaber matrix on the first entry (Bernoulli numbers)?”
In this presentation by Mathologer [this video] you can find the following slide: [LINK] relating the sum of the $n$ first $k$ powers of integers, i.e. $S_k$ and the Faulhaber matrix diagonals (which correspond to the columns highlighted on the image above. Here is the corresponding Faulhaber matrix: S 0 1 0 0 0 0 0 0 S 1 1/2 1/2 0 0 0 0 0 S 2 1/6 1/2 1/3 0 0 0 0 S 3 0 1/4 1/2 1/4 0 0 0 S 4 -1/30 0 1/3 1/2 1/5 0 0 S 5 0 -1/12 0 5/12 1/2 1/6 0 S 6 1/42 0 -1/6 0 1/2 1/2 1/7 The patterns along the first four columns are well explained: The harmonic sequence, $1/2$ 's, $k/12$ , $0$ 's, and then the following statement: Jacob Bernoulli discovered something amazing: The numbers in the different columns
Recommends feli_x · 2023-08 · Mathematics Stack Exchange · on “Search for a geometrical way to calculate the summations $\sum_{k=1}^n k^p$ ($p=1,2,3...$)”
There is an analogous geometrical view for the case $p=1$ in 2 dimensions. Look at Fig. 3 [LINK] , which illustrates the view for $n=4$ . The pyramid in 3d corresponds to the triangle in 2d. The sum $1+2+3+4$ can be calculated as the area of the pseudo-triangle. One can approximate this area as the area of the triangle which has the dashed line as one side and afterwards add 4 half squares extending beyond the dashed line. $S_1(4) = \frac{1}{2} \cdot 4 \cdot 4 + 4 \cdot \frac{1}{2} = 8 + 2 = 10$ . For arbitrary $n$ one arrives at the "Gauß-formula" $S_1(n) = \frac{1}{2} n \cdot n + \frac{n}{2} = \frac{1}{2} n \cdot (n+1)$ . This geometric proof is also shown in the video Power sum master cla
Recommends feli_x · 2023-08 · Mathematics Stack Exchange · on “Search for a geometrical way to calculate the summations $\sum_{k=1}^n k^p$ ($p=1,2,3...$)”
There exist geometrical proofs for the calculation of the sums $S_p(n):=\sum_{k=1}^nk^p$ for $p=1$ and $p=2$ (e.g. compilation of proofs for sum of squares and cubes [LINK] , understanding some PWoWs [LINK] ). The core question of this thread is: Does there exist a geometry-based method to prove the formulas of the above given summations, which is applicable for all integers $n$ and $k$ ? I found geometrical proofs for $p=2$ and $p=3$ , which I find beautiful. (I am sure other persons found these visualizations before, there are hints on this e.g. in the video Power sum master class [this video] .) The method of this proof for $p=2$ consists in interpreting the sum $1^2+2^2+3^3+...$ as the volume
Cites Toby Mak · 2019-11 · Mathematics Stack Exchange · on “When is it appropriate to find the integral of a function?”
The problem with using integration in your first example is that the function is discrete . For the whole of day $1$ , the population of ants is $1$ ; for the whole of day $2$ , the population of ants is $1+4=5$ , and so on. What you would have to integrate to get the correct result is a discrete function $f(x)$ , such that $f(x) = 0$ for $-1 ≤ x < 0$ , $f(x) = 1$ for $0 ≤ x < 1$ , $f(x) = 4$ for $1 ≤ x < 2$ and so on. For your second example, the case is the same. Because the total amount of sunlight is only given for each day $d$ , and not for all the times in the year, then using integration will not give the correct result. Since the number of summations is large ( $365$ days), this will