A Lower Bound and Several Exact Results on the $d$-Lucky Number

Sandi Klavžar, Indra Rajasingh, D. Ahima Emilet

If $\ell :V(G)\to \mathbb{N}$ is a vertex labeling of a graph $G=(V(G),E(G))$, then the $d$-lucky sum of a vertex $u\in V(G)$ is $d_\ell(u) = d_G(u) + \sum_{v\in N(u)}\…