3 problems

Let $F_n$ be the friendship graph formed by joining $n$ copies of $C_3$ at a central vertex. Let $m,n\in\mathbb{N}$ with $m\geq 1$. The known obstruction is that $F_n$ is not…

A family of graphs is weakly $A$-cordial if all but finitely many of its elements are $A$-cordial, where $A$ is an abelian group. Weak cordiality conjecture. For any abelian group…

Let $F_n$ be the friendship graph formed by joining $n$ copies of $C_3$ at a central vertex. For $m,n\in\mathbb{N}$ with $m\geq 1$, suppose that $F_n$ is obstructed from being…