  In this paper we summarise the localisation calculation of 5D super
Yang-Mills on simply connected toric Sasaki-Einstein (SE) manifolds. We show
how various aspects of the computation, including the equivariant index, the
asymptotic behaviour and the factorisation property are governed by the
combinatorial data of the toric geometry. We prove that the full perturbative
partition function on a simply connected SE manifold corresponding to an n-gon
toric diagram factorises to n copies of perturbative Nekrasov partition
function. This leads us to conjecture the full partition function as gluing n
copies of full Nekrasov partition function. This work is a generalisation of
some earlier computation carried out on $Y^{p,q}$ manifolds, whose moment map
cone has a quadrangle and our result is valid for manifolds whose moment map
cones have pentagon base, hexagon base, etc. The algorithm we used for dealing
with general cones may also be of independent interest.
