Maximum number of diagonal transversals in an extended self-orthogonal diagonal Latin square of order n, https://oeis.org/Axxxxxx

n=1, a(1)=1
Announcement: https://vk.com/wall162891802_2937, Eduard I. Vatutin, Jan 31 2025
Way of finding: brute force
0

n=2, a(2)=0
-

n=3, a(3)=0
-

n=4, a(4)=4
Announcement: https://vk.com/wall162891802_2937, Eduard I. Vatutin, Jan 31 2025
Way of finding: brute force
0 1 2 3 
2 3 0 1 
3 2 1 0 
1 0 3 2 

n=5, a(5)=5
Announcement: https://vk.com/wall162891802_2937, Eduard I. Vatutin, Jan 31 2025
Way of finding: brute force
0 1 2 3 4 
2 3 4 0 1 
4 0 1 2 3 
1 2 3 4 0 
3 4 0 1 2 

n=6, a(6)=0
-

n=7, a(7)=27
Announcement: https://vk.com/wall162891802_2937, Eduard I. Vatutin, Jan 31 2025
Way of finding: brute force
0 1 2 3 4 5 6 
2 3 1 5 6 4 0 
5 6 4 0 1 2 3 
4 0 6 2 3 1 5 
6 2 0 1 5 3 4 
1 5 3 4 0 6 2 
3 4 5 6 2 0 1 

n=8, a(8)=96
Announcement: https://vk.com/wall162891802_2937, Eduard I. Vatutin, Jan 31 2025
Way of finding: brute force
0 1 2 3 4 5 6 7 
2 3 0 1 6 7 4 5 
4 5 6 7 0 1 2 3 
6 7 4 5 2 3 0 1 
3 2 1 0 7 6 5 4 
1 0 3 2 5 4 7 6 
7 6 5 4 3 2 1 0 
5 4 7 6 1 0 3 2 

n=9, a(9)=333
Announcement: https://vk.com/wall162891802_2937, Eduard I. Vatutin, Jan 31 2025
Way of finding: brute force
0 1 2 3 4 5 6 7 8 
2 4 3 0 7 6 8 1 5 
5 0 6 8 2 1 4 3 7 
1 5 4 7 6 0 2 8 3 
6 2 8 5 3 4 7 0 1 
3 7 0 2 1 8 5 4 6 
8 3 5 6 0 7 1 2 4 
4 6 7 1 8 2 3 5 0 
7 8 1 4 5 3 0 6 2 

n=10, a(10)=152
Announcement: https://vk.com/wall162891802_2937, Eduard I. Vatutin, Jan 31 2025
Way of finding: brute force
0 1 2 3 4 5 6 7 8 9 
1 2 3 4 6 8 7 9 0 5 
2 4 9 7 8 3 0 1 5 6 
3 9 5 6 7 0 4 8 1 2 
8 7 0 1 5 2 9 6 3 4 
7 6 4 0 3 1 5 2 9 8 
4 3 1 5 2 9 8 0 6 7 
9 5 7 8 0 6 3 4 2 1 
5 8 6 9 1 4 2 3 7 0 
6 0 8 2 9 7 1 5 4 3 

Jan 31 2025