Abstract
A model Hamiltonian with 2-point, 4-point,..., 2n-point infinite-range interactions chosen in a particular way is introduced and the complete thermodynamics is obtained exactly in an elementary manner. The critical exponents alpha '=1-1/n, beta =1/2n, gamma = gamma '=1, delta =2n+1, Delta '=1+1/2n are derived and a minor violation of scaling is found.