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.
a(2) = -7: 2, 3; 3, 1. a(3) = -105: 2, 4, 5; 4, 5, 1; 5, 1, 3. a(4) = -1810: 4, 3, 7, 1; 3, 7, 1, 2; 7, 1, 2, 5; 1, 2, 5, 6.
a(2) = 11: 3, 2; 2, 5. a(3) = 286: 3, 11, 5; 11, 5, 7; 5, 7, 2. a(4) = 86087: 7, 3, 13, 17; 3, 13, 17, 2; 13, 17, 2, 11; 17, 2, 11, 5.
a[n_] := Max[Table[Det[HankelMatrix[Join[Drop[per = Part[Permutations[Prime[Range[2 n - 1]]], i], n], {Part[per, n]}], Join[{Part[per, n]}, Drop[per, - n]]]], {i, (2 n - 1) !}]]; Join[{1}, Array[a, 5]]
a(n) = my(v=[1..2*n-1], m=-oo, d); forperm(v, p, d = matdet(matrix(n, n, i, j, prime(p[i+j-1]))); if (d>m, m = d)); m; \\ Michel Marcus, Feb 08 2024
from itertools import permutations from sympy import primerange, prime, Matrix def A369947(n): return max(Matrix([p[i:i+n] for i in range(n)]).det() for p in permutations(primerange(prime((n<<1)-1)+1))) if n else 1 # Chai Wah Wu, Feb 12 2024
a[n_] := CountDistinct[Table[Det[HankelMatrix[Join[Drop[per = Part[Permutations[Range[2 n - 1]], i], n],{Part[per, n]}], Join[{Part[per, n]}, Drop[per, - n]]]], {i, (2 n - 1) !}]]; Join[{1}, Array[a, 5]]
a(n) = my(v=[1..2*n-1], list=List()); forperm(v, p, listput(list, matdet(matrix(n, n, i, j, p[i+j-1])));); #Set(list); \\ Michel Marcus, Feb 08 2024
from itertools import permutations from sympy import Matrix def A369942(n): return len({Matrix([p[i:i+n] for i in range(n)]).det() for p in permutations(range(1,n<<1))}) # Chai Wah Wu, Feb 12 2024