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# Category Archives: exposition

## 12160

12160 is an interesting number; but I didn’t know that until last night. As part of the work on semigroups, we are looking at the following problem. Given n and k, with n ≥ 2k, suppose that G is a k-homogeneous subgroup … Continue reading

Posted in doing mathematics, exposition
Tagged 4-homogeneous, permutation groups, semigroups
3 Comments

## An Aveiro theorem

When I was a child, one of the radio serials we listened to was The Lone Ranger. Typically, when the Lone Ranger with his sidekick Tonto had cleared up another mess of wrongdoing or whatever, he would say to Tonto, … Continue reading

## Orthogonal arrays and codes over rings

I have just posted to the arXiv a preprint of a paper with Josephine Kusuma about the subject in the title of this post. (Josephine is on the left in the picture, with Taoyang Wu; the water behind is Windermere.) … Continue reading

Posted in exposition
Tagged Delsarte, Gray map, Josephine Kusuma, orthogonal arrays, Z_4 codes
3 Comments

## Asymptotic group theory, 4

Thursday was a national holiday in Hungary, St Stephen’s Day if you are religious or traditional, Constitution Day if you are a communist. “The shrewd communists let the parliament pass the new constitution on August 20, 1949,” in the words … Continue reading

Posted in events, exposition
Tagged alternating groups, black box groups, coherent configurations, fireworks, St Stephen
1 Comment