Mathematical links

• Surfer
• GeoGebra
• The Online-Encyclopedia of Integer Sequences
• The UC Davis Front End for the arXiv, the preprint server for mathematics and physics papers
• Inverse Symbolic Calculator
• Journal of Combinatorial Theory, Series A
• Science Direct: Journal of Combinatorial Theory, Series A
• Zentralblatt
• The Electronic Journal of Combinatorics
• Séminaire Lotharingien de Combinatoire
• Research Institute for Symbolic Computation in Linz
• Mathematical Reviews
• Eric Weisstein's World of Mathematics
• Math Books online
• The Kuratowski Closure-Complement Problem