> #ATTENDANCE QUIZ FOR LECTURE 22 ; > #THE NUMBER OF ATTENDANCE QUESTIONS WERE: 8 ; > ; > #Q1 ; > #Write the above proof (if possible with more details) in your own words. ; > ; > #If we have a tree with 1 vertex, it should have 0 edge, n-(n-1) = 1- 0 = 1 ; > #proved ; > ; > #Q2 ; > #What is the OEIS A number of this sequence? ; > #[1,1,3,16,125,1296,16807...] ; > ; > #A000272 ; > ; > #Q3 ; > #Is this sequence ([0,0,1,15,222,3660, 68295...]) in the OEIS? If yes, what is the A-Number? ; > ; > #YES ; > #THE A NUMBER IS A057500 ; > #Q4 ; > #What is the smallest r such that ATreeSeq(30,r) is not in the OEIS? Optional: Submit it! ; > ; > #When r=13,ATreeSeq(30,r) is not in the OEIS ; > ; > #Q5 ; > #What is the ratio of the time it takes between time(TreeSeq(75)); and time(TreeSeq1(75));? ; > ; > #time(TreeSeq(75))/time(TreeSeq1(75)) ; > ; > #Q6 ; > # Let r_e(n) be the number of roots trees where every vertex has an even number of children. Set up a functional equation for egf of r_e(n).What are the first 20 terms of this sequence? Is it in the OEIS? ; > #Q7 ; > #How many labelled trees are there with 27 vertices and 6 leaves? ; > ; > #coeff(TreeSeqL(27, t)[27], t, 6) ; > #5466338131409680923049107456000000 ; > ; > #Q8 ; > #Conjecture an explicit formula for the average number of leaves of a labeled trees with n vertices. ; > #A bigger challenge: What is the limit if you divide by n > An even bigger challenge: prove the conjecture ;