HamiltonianCycle[g] finds a Hamiltonian cycle in graph g if one exists. HamiltonianCycle[g, All] gives all Hamiltonian cycles of graph g.

HamiltonianQ[g] yields True if there exists a Hamiltonian cycle in graph g, or in other words, if there exists a cycle that visits each vertex exactly once.

Harary[k, n] constructs the minimal k-connected graph on n vertices.

HideCycles[c] canonically encodes the cycle structure c into a unique permutation.

IdenticalQ[g, h] yields True if graphs g and h have identical edge lists, even though the associated graphics information need not be the same.

InDegree[g, n] returns the in-degree of vertex n in directed graph g. InDegree[g] returns the sequence of in-degrees of the vertices in directed graph g.

Index[p] gives the index of permutation p, the sum of all subscripts j such that p[[j]] is greater than p[[j + 1]].

InsertIntoTableau[e, t] inserts integer e into Young tableau t using the bumping algorithm. InsertIntoTableau[e, t, All] inserts e into Young tableau t and returns the new ...

Involutions[l] gives the list of involutions of the elements in the list l. Involutions[l, Cycles] gives the involutions in their cycle representation. Involution[n] gives ...

KSubsets[l, k] gives all subsets of set l containing exactly k elements, ordered lexicographically.