Now showing items 1-3 of 3
On the number of unique subgraphs
(Elsevier, 1973-10)
Entringer and Erdos introduced the concept of a unique subgraph of a given graph G and obtained a lower bound for the maximum number of unique subgraphs in any n-point graph, which we now improve.
The number of caterpillars
(Elsevier, 1973)
A caterpillar is a tree which metamorphoses into a path when its cocoon of endpoints is removed. The number of nonisomorphic caterpillars with n+4 points is 2n + 2[n/2]. This neat formula is proved in two ways: first, as ...