[en] E.g.f.: x^2/(x+3-2*exp(x)). [en] Number of associative and quasitrivial binary operations on {1,...,n} that have both neutral and annihilator elements.
Disciplines :
Computer science Mathematics
Author, co-author :
Marichal, Jean-Luc ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Mathematics Research Unit