What's the Clojure equivalent of inject:into: in Smalltalk?

I'm trying to learn Clojure but my synapses seem to be hard-wired to Smalltalk.

What's the equivalent of this function?

[:n :k | (1 to: k) inject: 1 into: [:c :i | c * (n - k + i / i)]]

• this is the binomial coefficient for n, k - also known as "choose" function, representing the number of combinations of n things taken k times