#ATTENDANCE QUIZ FOR LECTURE 18 of Dr. Z.'s Math454(02) Rutgers University

# Please Edit this .txt page with Answers

#Email  ShaloshBEkhad@gmail.com 
#Subject: p18
#with an attachment called
#p18FirstLast.txt
#(e.g. p18DoronZeilberger.txt)

#Right after finishing watching the lecture but no later than Nov. 10, 2020, 8:00pm


THE NUMBER OF ATTENDANCE QUESTIONS WERE:

PLEASE LIST ALL THE QUESTIONS FOLLOWED, AFTER EACH, BY THE ANSWER

Q1. 
	Who invented latin squares and latin-greco graph

A1. 
	Leonhard Euler

Q2. 
	What is nops(AllGraphs(20))? [No commands]

A2. 
	20 vertices can have at most 20C2 different edges. And we can pick any number of edges from that to form a unique graph. The answer would be the size of powerset(20C2) = 2^(20C2) = 1569275433846670190958947355801916604025588861116008628224

Q3. 
	What is CC(G, 38)? 
A3. 
	CC(G, 38) = {1, 38} = CC(G, 1)

Q4.
	Is this sequence in OEIS? [number and description]
	[1, 1, 4, 38, 728]

A4. 
	Yes, A1187, description is number of connected labeled graphs with n nodes 

Q5.
	Draw this graph manually

A5. 
	8-1-4-6-9
	        |
	  2-7-5-3
          |
          10

Q6. 
	Is this sequence in OEIS? 
	What is the number of connected trees with 20 verticies 

A6. 
	Yes, A272, description is number of connected labeled trees with n nodes 
	20 vertices: 5480386857784802185939 (based on OEIS)

Q7. 
	Is this in the OEIS? 
	What is the A-number and the description
A7. 
	Yes, A57500, number of connected labeled graphs with n edges and n nodes 

Q8. 
	Is this in the OEIS? 
A8. 
	Yes, A61540, Number of connected labeled graphs with n nodes and n+1 edges.