# Graph 1(d) with 41 nodes and 82 edges
# Degree hist:[0, 0, 0, 0, 41] deg max: 4 avg. deg. 4.0
# Diameter: 3  Avg. Dist.: 2.503659   
#
# Obtained from 1(c) by the 2-swap [(17,20), (28,31) to (17,31), (28,20)].
# J. Allwright, New (Delta, D) graphs discovered by heuristic search. 
# Discrete Appl. Math., 37/38 (1992), pp.3-8.
# https://doi.org/10.1016/0166-218X(92)90120-Y
# 
0 2 1 11 22
2 6 7 8
1 3 4 5
3 9 37 39
4 33 35 10
5 6 21 31
6 20 32
7 34 36 9
8 10 38 40
9 28 16
37 18 25 38
39 19 26 40
33 14 34 25
35 15 29 36
10 17 27
34 19 30
36 18 26
38 14 29
40 15 30
20 15 25 28
32 19 29 27
21 18 16 30
31 14 17 26
11 12 13 22
12 16 15 14
13 17 18 19
16 27
17 28
18
19
15
14
22 23 24
23 27 26 25
24 28 29 30
28
29
30
27
26
25