I am not sure I understand it either because the answer seems to easy once you know about Complete Graphs.
The complete graph on n vertices is denoted by Kn .
If you look at all of the occurrences of the sequence in OEIS A000217 one of them is
Number of edges in complete graph of order n, K_n.
So my take is the number 46 is the difference between two of the numbers, where each number represents the number of stations. The two numbers (n) with the proper difference is 1081 and 1035.
However for a K_n graph the connections have no direction but the tickets have a direction, e.g. from A to B would be one edge and from B to A would be another edge, so the relationship needs to account for this. This is easily handled by noting that for each edge in the K_n graph they would need to be doubled so a relationship of 2 needs to be used for the edges in the calculation.
Here is the table I get
n K_n K_n
directed Diff
0 0 0
1 1 2 2
2 3 6 4
3 6 12 6
4 10 20 8
5 15 30 10
6 21 42 12
7 28 56 14
8 36 72 16
9 45 90 18
10 55 110 20
11 66 132 22
12 78 156 24
13 91 182 26
14 105 210 28
15 120 240 30
16 136 272 32
17 153 306 34
18 171 342 36
19 190 380 38
20 210 420 40
21 231 462 42
22 253 506 44
23 276 552 46
24 300 600 48
25 325 650 50
26 351 702 52
27 378 756 54
28 406 812 56
29 435 870 58
30 465 930 60
31 496 992 62
32 528 1056 64
33 561 1122 66
34 595 1190 68
35 630 1260 70
36 666 1332 72
37 703 1406 74
38 741 1482 76
39 780 1560 78
40 820 1640 80
41 861 1722 82
42 903 1806 84
43 946 1892 86
44 990 1980 88
45 1035 2070 90
46 1081 2162 92
47 1128 2256 94
48 1176 2352 96
49 1225 2450 98
50 1275 2550 100
51 1326 2652 102
52 1378 2756 104
53 1431 2862 106
Looking at the Diff list we find 46 when there are 23 stations (n), so the number of existing stations before 1 is added is 22.
Also there could be more than one station added in which case the sum of the values in the Diff list need to sum to 46 but also have the constraint that they are consecutive and start at one greater than the number of existing stations, e.g. 22 + 24 = 46 thus the number of existing stations is 10.