This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A379145 #16 Apr 09 2025 09:52:14 %S A379145 0,2,64,49152,478150656 %N A379145 Number of horizontal plane Brown's diagonal Latin squares of order 2n with the first row in order. %C A379145 A Brown's diagonal Latin square is a horizontally symmetric row-inverse (horizontal plane Brown's diagonal Latin square) or vertically symmetric column-inverse diagonal Latin square (vertical plane Brown's diagonal Latin square). Diagonal Latin squares of this type have interesting properties, for example, a large number of transversals. %C A379145 Also number of vertical plane Brown's diagonal Latin squares of order 2n with the first row in order. %C A379145 Plain symmetry diagonal Latin squares do not exist for odd orders. %H A379145 E. I. Vatutin, <a href="http://evatutin.narod.ru/evatutin_dls_spec_types_list.pdf">Special types of diagonal Latin squares</a>, Cloud and distributed computing systems in electronic control conference, within the National supercomputing forum (NSCF - 2022). Pereslavl-Zalessky, 2023. pp. 9-18. (in Russian) %H A379145 Eduard I. Vatutin, <a href="https://vk.com/wall162891802_1471">Enumeration of the Brown's diagonal Latin squares of orders 1-9</a> (in Russian). %H A379145 Eduard I. Vatutin, <a href="https://vk.com/wall162891802_2894">Clarification for Brown's diagonal Latin squares for orders 6 and 8</a> (in Russian). %H A379145 <a href="/index/La#Latin">Index entries for sequences related to Latin squares and rectangles</a>. %F A379145 a(n) = A381626(n) / (2n)!. %Y A379145 Cf. A287649, A339305, A339641, A340186, A381626. %K A379145 nonn,more,hard %O A379145 1,2 %A A379145 _Eduard I. Vatutin_, Dec 16 2024 %E A379145 a(5) added by Oleg S. Zaikin and _Eduard I. Vatutin_, Apr 08 2025