Number of main classes of pandiagonal Latin squares of order n, https://oeis.org/A339999 n=1, a(1)=1 Announcement: https://vk.com/wall162891802_1538, Eduard I. Vatutin, Feb 01 2021 # 1 0 n=5, a(5)=1 Announcement: https://vk.com/wall162891802_1538, Eduard I. Vatutin, Feb 01 2021 # 1 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=7, a(7)=1 Announcement: https://vk.com/wall162891802_1538, Eduard I. Vatutin, Feb 01 2021 # 1 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=11, a(11)=2 Announcement: https://vk.com/wall162891802_1538, Eduard I. Vatutin, Feb 01 2021 # 1 0 1 2 3 4 5 6 7 8 9 10 2 3 1 4 5 6 7 9 10 8 0 6 9 7 8 10 0 2 1 4 3 5 7 8 9 10 0 2 1 3 5 4 6 1 4 3 5 6 7 9 8 0 10 2 9 10 8 0 2 1 3 4 6 5 7 3 5 4 6 7 9 8 10 2 0 1 8 0 10 2 1 3 4 5 7 6 9 10 2 0 1 3 4 5 6 9 7 8 4 6 5 7 9 8 10 0 1 2 3 5 7 6 9 8 10 0 2 3 1 4 # 2 0 1 2 3 4 5 6 7 8 9 10 2 3 4 5 1 7 8 9 10 6 0 3 9 5 6 7 8 2 10 4 0 1 5 6 7 8 9 10 4 0 1 2 3 6 0 8 2 10 4 5 1 7 3 9 8 2 10 4 0 1 7 3 9 5 6 10 4 0 1 2 3 9 5 6 7 8 4 5 1 7 3 9 10 6 0 8 2 1 7 3 9 5 6 0 8 2 10 4 7 8 9 10 6 0 1 2 3 4 5 9 10 6 0 8 2 3 4 5 1 7 Feb 01 2021