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 A309259 #22 Mar 14 2020 17:21:54
%S A309259 1,3,18,80,75,63,196,144,405
%N A309259 a(n) is the greatest common divisor of the determinants of order n Latin squares.
%C A309259 We apply every symbol permutation on the representatives of isotopic classes to generate Latin squares of order n and calculate the determinants. We then compute the greatest common divisor of the values obtained.
%C A309259 These results are based upon work supported by the National Science Foundation under the grants numbered DMS-1852378 and DMS-1560019.
%H A309259 Peterson Lenard, <a href="/A309259/a309259.sage.txt">Greatest Common Divisor of all determinants</a>
%H A309259 Brendan McKay, <a href="https://users.cecs.anu.edu.au/~bdm/data/latin.html">Combinatorial Data</a>
%e A309259 For n=4, the set of absolute values of the determinants is {0, 80, 160}, so the greatest common divisor of the determinants is 80. Therefore, a(4)=80.
%o A309259 (Sage) # See Peterson Lenard link
%Y A309259 Cf. A301371, A308853, A309088, A309258.
%K A309259 nonn,hard,more
%O A309259 1,2
%A A309259 _Alvaro R. Belmonte_,_Eugene Fiorini__,_Peterson Lenard_, _Froylan Maldonado_, _Sabrina Traver_, _Wing Hong Tony Wong_, Jul 19 2019
%E A309259 a(8), a(9) from _Hugo Pfoertner_, Sep 02 2019