Desmos Graphing Calculator

I've been familiar with the Desmos Graphing Calculator since October of 2015 but my last saved file was from October 2016. While watching a video from 3Blue1Brown, I was reminded of this resource again because he made use of it when illustrating graphical properties of quadratic functions. It's remarkably easy to use. I watched a series of short YouTube videos about the Desmos Graphing Calculator, just to refresh my memory and then I was away. It's easy to embed a graph into a blog post as I've done below: 

It's all remarkably easy. In this example, I've hidden the graph of the derivative function but used it to create the tangent to the curve at any point. The slider changes the x value of the point where the tangent touches the graph of \(y=x^x\) and the slope of the tangent changes accordingly.

I'm thinking that I could make use of this resource in the daily analysis of my diurnal age. For example, on July 28th 2020 I was 26049 days old. One of the properties of this number is that it is:

... a member of OEIS A064808: the (n+1)st (n+2)-gonal number (here n=37 so we have the 38th 39-gonal number). The formula is a(n) = (n + 1)*(n^2 + 2)/2 and the sequence, up to and including 26049, can be generated from the following SageMath code:

INPUT

L=[]

for n in [0..37]:

    number=(n + 1)*(n^2 + 2)/2

    L.append(number)

print(L)

OUTPUT

[1, 3, 9, 22, 45, 81, 133, 204, 297, 415, 561, 738, 949, 1197, 1485, 1816, 2193, 2619, 3097, 3630, 4221, 4873, 5589, 6372, 7225, 8151, 9153, 10234, 11397, 12645, 13981, 15408, 16929, 18547, 20265, 22086, 24013, 26049]

This relationship can be easily graphed and a corresponding table drawn up as shown in the embedded graph below:

It's not all that useful here as SageMath can easily produce the same output but it's a little different and could prove useful in the future as an aid to representation and analysis. The table is not visible above but looks like this: