In the title compound, C(21)H(33)FN(3)O(2)P, the P atom has a distorted tetra-hedral environment and the N atoms display geometries consistent with a model of sp(2) hybridization (with bond-angle sums for the tertiary N atoms of 357.8 and 358.7°). The phosphoryl and carbonyl groups are anti with respect to each other. In the crystal, inversion dimers linked by pairs of N-H⋯O hydrogen bonds gene...

N, N΄-3, 4-di(methylamino)-1, 2, 5-oxadiazole (1f) was prepared by dehydration of N, N΄-3, 4-di(methylamino)glyoxime (2f) in aqueous potassium hydroxid at 170-180 ˚C. Under similar conditions N, N΄-3, 4-di(benzylamino)-1, 2, 5-oxadiazole (1c) and N, N΄-3, 4-di(isopropylamino)...

We investigate the long-term behavior of solutions of the difference equation[ x_{n+1}=x_{n}x_{n-3}-1 ,, n=0 ,, 1 ,, ldots ,, ]noindent where the initial conditions $x_{-3} ,, x_{-2} ,, x_{-1} ,, x_{0}$ are real numbers.  In particular, we look at the periodicity and asymptotic periodicity of solutions, as well as the existence of unbounded solutions.