Hydrogen bonds: 1 donor with 2 acceptors at the same time possible (or vice versa)?

Can 1 donor (eg N-H) facilitate 2 H-bonds with 2 different acceptors (eg 2x O) at the same time (assuming that both are within range and angle constraint)? i.e. building an "h-bond triangle"?


Is it possible the other way round: 2 donors and 1 acceptor at the same time?


