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Dairy, May 2018

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Tuesday, May 1, 2018

428,362 sets of equations

I calculated that there are 428,362 sets of equations for the the Irregular Chocolate Bar problem for the problem of finding 22 unique integers which can be divided in up to and including 10 partitions. (This calculation took 13 hours 39 minutes.) So far, my program has searched 62,378 of these sets of equations and found 959 solution with some duplicates resulting in 554 unique solutions. It looks like the program will require some more months to search the remaining sets of equations.

Thursday, May 3, 2018

Three Dune Books

At 09:49, I bought the following three book from charity shop Het Goed, for € 0.95 each, all written in English and published by New English Library:

I have now all books of the Dune series written by Frank Herbert both in English as in Dutch. I have not read all of them in both languages.

Monday, May 7, 2018


This afternoon, I bought a print of the woodcut 'Droomkoppel' from Willemijn Calis, which I saw on April 14 at the exhibition 'China Dreams'.

Wednesday, May 9, 2018


At 9:52, I bought the following two books from charity shop Het Goed: At 17:10, I bought the following seven comics (all in Dutch) from Valérian and Laureline series, drawn by Jean-Claude Mézières after a scenario by Pierre Christin, and published by Dargaud:

Saturday, May 19, 2018

Daries of Doeschka Meijsing

I finished reading the book En liefde in mindere mate: dagboeken 1961-1987 about the diaries of Doeschka Meijsing, a Dutch novelist. This is part one, as she died in 2012. It seems that the second part has not been published yet. Almost half of the book consists of notes. Some of the notes, contain back ground information that is not really relevant for understanding the diary. The editors of the diaries, made a selection of her diary. They did not give information about the ratio of entries they selected. I felt they might have better included more entries and make the notes more concise. It was an interested read. It does show, as so many biographies before, that people wrestle for many years with problems in their lives and have a very hard time to change there basic habits.

Sunday, May 20, 2018

Three fold rotation symmetry

I thought about a way to visualize the long sequence of coloured rubber straps, and I came up with the following figure:

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In this figure there are ten triangles, one for each combination of the five coloured rubber strapts, such that the vertices are on a circle representing the repeated sequence. There are fifteen pairs of parallel lines, where each pair represent two combination occuring in both directions along the sequence. At first sight the figure seems to have some mirror symmetries, but actual it has a three fold rotation symmetry.

This months interesting links

Home | April 2018