This is a heavily interactive web application, and JavaScript is required. Simple HTML interfaces are possible, but that is not what this is.
Post
Jan Marthedal Rasmussen
janmr.com
did:plc:vu6qczmz4fwvt5hylbxjlcd6
Langford pairs: Arrange the 2n numbers {1, 1, 2, 2, ..., n, n} such that exactly k numbers occur between the two appearances of each digit k dialectrix.com/langford.html #math #combinatorics
2025-12-06T14:52:57.334Z