The number of rhombus tilings of a "punctured" hexagon and the minor summation formula

Soichi Okada, Christian Krattenthaler

We compute the number of all rhombus tilings of a hexagon with sides $a,b+1,c,a+1,b,c+1$, of which the central triangle is removed, provided $a,b,c$ have the same parity. The resul…