Collections

Every collection head in @enumeratio/collections — the enumerable families (Subsets, SymmetricGroup, IntegerPartitions, …) and the set operations over them. Each is a lazy indexed family: Count is closed-form and At unranks. The badge is the head's signature. Enumerable families carry their own symbol page with a live table; see the collection table to page any of them. The OEIS numbers are established by count — the family's own kernel for the first sizes, matched against the sequence's terms — and a ✓ says so.