# Discrete Mathematics

Discrete Mathematics > 1994 > 135 > 1-3 > 371-375

Discrete Mathematics > 1994 > 135 > 1-3 > 93-101

_{1}= 1 ,a

_{n}

_{+}

_{1}= sa

_{n}+ t θa

_{m}, where s, t are integers, and θ is a quadratic irrationality. Under appropriate hypotheses (especially that s + tθ be a PV-number) it is proved that the highest power of Δ that dividesa

_{n}, where Δ is the discriminant of θ, tends...

Discrete Mathematics > 1994 > 135 > 1-3 > 15-28

Discrete Mathematics > 1994 > 135 > 1-3 > 61-68

_{υ}with a common vertex. A bowtie system is an edge disjoint decomposition of K

_{υ}into bowties. A bowtie system is 2-perfect if it has the additional property that each bowtie can be replaced by exactly one of its distance 2 graphs so that the resulting collection of bowties is also a bowtie system. We show that the spectrum of 2-perfect...

Discrete Mathematics > 1994 > 135 > 1-3 > 359-365

_{1}G

_{2}, G

_{1}+ G

_{2}, G

_{1}[G

_{2}], G

_{1}G

_{2}and G

_{1}{G

_{2}} be the product, join, composition, corona and cluster, respectively, of the graphs G

_{1}and G

_{2}. We compute the sume of distances between all pairs of vertices in these composite graphs.

Discrete Mathematics > 1994 > 135 > 1-3 > 163-168

Discrete Mathematics > 1994 > 135 > 1-3 > 153-161

^{n}leaves. This paper further investigates an infinite family of primary trees with binary structures by means of an algorithm related to the matching theory...

Discrete Mathematics > 1994 > 135 > 1-3 > 387-393

Discrete Mathematics > 1994 > 135 > 1-3 > 177-191

Discrete Mathematics > 1994 > 135 > 1-3 > 69-79

Discrete Mathematics > 1994 > 135 > 1-3 > 47-59

Discrete Mathematics > 1994 > 135 > 1-3 > 377-379

_{p}.

Discrete Mathematics > 1994 > 135 > 1-3 > 193-223

Discrete Mathematics > 1994 > 135 > 1-3 > 279-286

_{G}(λ) denote the number of ways to T-color G with numbers from the set {1, 2, , λ}. We show that there is a polynomial, Q

_{G}(λ), such that Q

_{G}(λ) = T ...

Discrete Mathematics > 1994 > 135 > 1-3 > 225-232

Discrete Mathematics > 1994 > 135 > 1-3 > 233-243

Discrete Mathematics > 1994 > 135 > 1-3 > 335-347

_{0}x

_{1}x

_{m}there is a directed path y

_{0}y

_{1}y

_{k}such that x

_{0}=y

_{0}, x

_{m}= y

_{k}, and {y

_{i}0 i k} {x

_{i}0 i m }. We describe the structure of those (m, 1)-transitive and (3, 2)-transitive directed graphs in which each...

Discrete Mathematics > 1994 > 135 > 1-3 > 169-176

Discrete Mathematics > 1994 > 135 > 1-3 > 367-369

Discrete Mathematics > 1994 > 135 > 1-3 > 81-92