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On this page are computer-accessible forms for the graph C4[ 20, 3 ] = R_10(7,6).

(I) Following is a form readable by MAGMA:

g:=Graph<20|{ {2, 3}, {6, 7}, {4, 5}, {8, 9}, {1, 2}, {5, 6}, {8, 11}, {9, 10}, {11, 15}, {16, 20}, {9, 12}, {3, 4}, {10, 13}, {1, 11}, {5, 15}, {4, 14}, {1, 10}, {2, 15}, {2, 12}, {3, 13}, {1, 14}, {7, 8}, {3, 16}, {7, 20}, {4, 17}, {6, 19}, {6, 16}, {7, 17}, {5, 18}, {8, 18}, {14, 20}, {11, 17}, {9, 19}, {12, 16}, {15, 19}, {14, 18}, {13, 17}, {10, 20}, {13, 19}, {12, 18} }>;

(II) A more general form is to represent the graph as the orbit of {2, 3} under the group generated by the following permutations:

a: (3, 12)(4, 9)(5, 19)(8, 17)(10, 14)(13, 18)
b: (4, 13)(5, 19)(9, 18)(10, 14)
c: (2, 10, 11, 14)(3, 13, 17, 4)(5, 16, 19, 7)(8, 18, 12, 9)(15, 20)
d: (1, 2)(3, 14)(5, 17)(6, 7)(8, 19)(10, 12)(11, 15)(13, 18)(16, 20)

(III) Last is Groups&Graphs. Copy everything between (not including) the lines of asterisks into a plain text file and save it as "graph.txt". Then launch G&G (Groups&Graphs) and select Read Text from the File menu.

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&Graph
C4[ 20, 3 ]
20
-1 11 2 14 10
-2 1 12 3 15
-3 2 13 4 16
-4 3 14 5 17
-5 4 15 6 18
-6 5 16 7 19
-7 6 17 8 20
-8 11 7 18 9
-9 12 8 19 10
-10 1 13 9 20
-11 1 15 17 8
-12 2 16 18 9
-13 3 17 19 10
-14 1 4 18 20
-15 11 2 5 19
-16 12 3 6 20
-17 11 13 4 7
-18 12 14 5 8
-19 13 15 6 9
-20 14 16 7 10
0

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