**The project moved to a new server on May 6, 2019 – please report back any issues you might encounter!**

This

**collaborative project**is- a
**database of combinatorial statistics and maps**on combinatorial collections and - a
**search engine**, identifying your data as the**composition of known maps and statistics**. - a
**combinatorial collection**is a collection $\mathcal{S} = \bigcup_{x}\mathcal{S}_x$ of finite sets $\mathcal{S}_x$ (e.g. the set of permutations) - a
**combinatorial map**is a map $\phi: \mathcal{S} \longrightarrow \mathcal{S'}$ between collections (e.g. the inverse of a permutation) - a
**combinatorial statistic**(or**parameter**) is a map $\operatorname{st}: \mathcal{S} \longrightarrow \mathbb{Z}$ (e.g. the order of a permutation) - the database currently contains
**1398 statistics**and**146 maps**on**18 collections**

There is a detailed usage example and several MathOverflow discussions with examples of the database usage.