On Jun 22, 2024, Jimso wrote:
I suggest that you reread the full discussion on this thread and the others that are mentioned near the beginning. There is some wisdom in that discussion that can be overlooked on first reading.

What you are looking for is any of several path-based methods, in which you enter the numbers in order, following an order that is logical to you but mysterious to others. You can match any sum using a sequence of numbers that is either continuous (when the sum is divisible by 2 but not 4, like 34) or skips at most one number in all other cases. You can start the count in any cell. The Euphoria method in Melencolia has those properties, and it may be your best option. I published several different path methods (some of which might be preferable for varying teasons) in my book, Easy Magic Square Methods and Tricks. Although I am partial to my own methods, I realize that the international shipping costs for my hardback books are ridiculous.

You can find what you need at lybrary.com. In addition to Melencolia and the Werner Miller options, you should consider Mostly Perfect and Perfectly Possible by Michael Daniels. (There is a low-cost combination package at lybrary.com.). Also, you could learn a very easy method for a birthday square from a recent lecture video by Art Benjamin, available by download from vanishingincmagic.com.

All of the newer methods are far superior to the old way of doing it.