In this paper, we are going to analyze the following difference equation $$x_{n+1}=\frac{x_{n-29}}{1+x_{n-4}x_{n-9}x_{n-14}x_{n-19}x_{n-24}} \quad n=0,1,2,...$$ where $x_{-29}, x_{-28}, x_{-27}, ..., x_{-2}, x_{-1}, x_{0} \in \left(0,\infty\right)$.

In the title centrosymmetric dinuclear nickel complex, [Ni(2)(C(22)H(30)N(4)O(2))(NO(3))(2)], each of the two Ni(II) atoms has a distorted octa-hedral geometry, defined by two N atoms and two O atoms from the macrocyclic ligand and two O atoms from a chelating nitrate anion. The two Ni atoms are bridged by two phenolate O atoms, forming a four-membered Ni(2)O(2) ring.

In the centrosymmetric and dinuclear title complex, [Mn(2)(C(22)H(22)N(4)O(2))(ClO(4))(2)], the two Mn atoms are bridged by two phenolate O atoms of the N(4)O(2) macrocycle with an Mn⋯Mn distance of 2.9228 (11) Å. The distorted square-pyramidal N(2)O(3) coordination geometry is completed by an O atom derived from a perchlorate anion.