tabulate(e, k, lo, hi) — evaluates e at each integer k in [lo, hi], as a row matrix.
The generic answer to "how do I get a list of terms?" It is not specific to the sequences: tabulate(binom(4, k), k, 0, 4) is a Pascal row and tabulate(k^2, k, 1, 5) the squares, so every function in the library gains a tabulated form from one node.
The result is a 1xnmatrix._Matrix, which is already this project's carrier for a sequence of values — eigen(A) returns one — so indexing with at(r, 1, k), tuple assignment, the matrix operations, pretty-printing and :save all come for free.
k is a binder: excluded from children and carried through rebuild, so substitute cannot rewrite it, while lo and hi are ordinary children — the _DefIntegral convention. The index is bound as a _Number, matching _DefIntegral and sample; a term that does not fold stays symbolic in its cell.
