Abstract We show that the number of signed permutations avoiding 1234 equals the number of signed permutations avoiding 2143 (also called vexillary signed permutations), resolving a conjecture by Anderson and Fulton. The main tool that we use is the generating tree developed by West. Many further directions are mentioned in the end.

中文翻译：

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计数有符号的vexillary排列

摘要 我们证明了避开 1234 的有符号排列的数量等于避开 2143 的有符号排列的数量（也称为 vexillary 有符号排列），解决了 Anderson 和 Fulton 的猜想。我们使用的主要工具是 West 开发的生成树。最后提到了许多进一步的方向。