Open Total Even Periods

n=2
2 1

n=3
3 3

n=4
4 4

n=5
2 1

n=6
6 4

n=7
3 1
7 7

n=8
2 1
8 9

n=9
4 1

n=10
10 9

n=11
2 1
3 1
11 13

n=12
12 16

n=13
6 1

n=14
2 1
4 1
14 16

n=15
3 1
7 1
15 21

n=16
16 25

n=17
2 1
8 1

n=18
18 25

n=19
3 1
4 1
19 31

n=20
2 1
6 1
20 36

Total Even Periods
(Closed neighborhoods)

n=2
1 1
3 2

n=3
2 3
5 2

n=4
4 3

n=5
1 1
2 1
3 3
5 1
7 4
11 3

n=6
8 7

n=7
2 1
5 4
11 8

n=8
1 1
6 7
13 12

n=9
2 1
4 1
14 3

n=11
1 1
2 1
5 3
7 9
11 6
15 2

n=13
2 1
8 12

n=14
1 1
4 1
9 3
16 1

n=15
2 1
11 2
23 4

n=16
14 1

n=17
1 1
2 1
13 1

n=18
none

n=19
2 1
4 1