In this parer, we consider Padovan numbers with different initial values. We
define the Gadovan numbers which generalizes a new class of Padovan numbers, and we
derive Binet-like formulas, generating functions, exponential generating functions for the
Gadovan numbers. Also, we obtain binomial sums, some identities and a matrix of the
Gadovan numbers.
In this article, we construct the plastic number in the three-dimensional
space. We examine the nested radicals and continued fraction expansions of the plastic ratio.
In addition, we give some properties and geometric interpretations of the plastic constant.