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 A369949 #15 Feb 12 2024 12:41:43
%S A369949 1,1,3,59,2459,174063,19141721
%N A369949 a(n) is the number of distinct values of the determinant of an n X n Hankel matrix using the first 2*n - 1 prime numbers.
%H A369949 Wikipedia, <a href="https://en.wikipedia.org/wiki/Hankel_matrix">Hankel matrix</a>.
%t A369949 a[n_] := CountDistinct[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]]
%o A369949 (PARI) a(n) = my(v=[1..2*n-1], list=List()); forperm(v, p, listput(list, matdet(matrix(n, n, i, j, prime(p[i+j-1]))));); #Set(list); \\ _Michel Marcus_, Feb 08 2024
%o A369949 (Python)
%o A369949 from itertools import permutations
%o A369949 from sympy import primerange, prime, Matrix
%o A369949 def A369949(n): return len({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
%Y A369949 Cf. A024356, A369946, A369947, A350933.
%K A369949 nonn,hard,more
%O A369949 0,3
%A A369949 _Stefano Spezia_, Feb 06 2024
%E A369949 a(6) from _Michel Marcus_, Feb 08 2024