Algebraic combinatorics - Combinatorics (sagemath.org)
The On-Line Encyclopedia of Integer Sequences® (OEIS®)
- FindStat
Database of Permutation Pattern Avoidance (depaul.edu)
Index and list of polynomials (symmetricfunctions.com)
Characters of the Symmetric Group
dept.math.lsa.umich.edu/~jrs/archive.html