This is a direct continuation of my last post on factoring. In this post, we will look into some of the more intricate refinements of Fermat’s Method of Factorization.
After my previous posts (I, II) on perfect partitions of numbers, I continued to play with the relationship between compositions and partitions of different numbers. I ended up stumbling across the following idea: which numbers can be represented as a sum of consecutive positive integers? This seems to be another well-known question, but I haven’t come across it before.
Yavor Kirov April 14, 2021 at 3:24 am on Long live opalstack!Thabk you! I was looking for an opinion of a long-term user of Opalstack so your answer was exactly what I needed. 
David Lowry-Duda April 13, 2021 at 9:32 pm on Long live opalstack!Hi Yavor, I'm very happy with Opalstack. After the initial transition, there have been almost no problems. I'll note that for a few months, opalstack's email setup was rocky, but they figured that out. I'd recommend it. They've been pretty responsive to problems, too. You can see what's troubling people now on their community/support forum: https://community.opalstack.com/. I know a somewhat ---Yavor Kirov April 13, 2021 at 6:12 pm on Long live opalstack!Hello David, Would you please be so kind to tell us (me) of your (further) experience with Opalstack so far? I myself had to migrate away from WebFaction and I am wondering if now migrating some of my sites to Opalstack is a good idea. Best regards :) 
Tomek March 18, 2021 at 5:09 pm on A response to FtYoU’s question on RedditGod bless you David. Great explanation! David Lowry-Duda February 25, 2021 at 6:24 pm on phase_mag_plot: a sage package for plotting complex functionsI'm glad to hear it! I would also read issues or pull requests on github. I think it would not be particularly hard to incorporate this into official sage. I have a local build of sage that includes a variant of phase_mag_plot as the default complex_plot. There are a few additional usability things I need to do before submitting this ---
Jan van Delden February 25, 2021 at 5:07 pm on phase_mag_plot: a sage package for plotting complex functionsI took the liberty to download your SageMath module and changed a few options. Since I was not completely clear on the interaction between lightness and color (defined by the argument of the function to be displayed) I decided to weigh these differently. Color, from the colorwheel by 0.8 and lightness by 0.2. I computed the color first and weighed ---
eliot December 23, 2020 at 4:07 pm on Trigonometric and related substitutions in integralsFor Euler substitutions, do you mind explaining the reasoning for the t term in x*sqrt(a) + t. Is there anywhere else I can read up on this? Thanks for this post! David Lowry-Duda August 7, 2020 at 4:15 pm on AboutThat's great! If there are particular plots that you're interested in, let me know. But I (very recently) posted a library for making the plots https://davidlowryduda.com/phase_mag_plot-a-sage-package-for-plotting-complex-functions/ Alternately, I make sage/python notebooks available for many of my visualizations. These are usually linked to within the post. If you see something that you want to replicate and find the code, leave a ---
Nguyen Xuan Son April 11, 2020 at 4:53 pm on AboutHi Could you please share the python code to generating beautiful plots? I plan to use it for my son to get interested in python programming. Son David Lowry-Duda October 17, 2019 at 3:17 pm on Notes from a talk at the Maine-Quebec Number Theory ConferenceThanks Peter! You're right --- and it's a nice reference.