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 A369835 #11 Feb 11 2024 11:28:44
%S A369835 1,1,1,6,23,119,718,5038,40320,362879
%N A369835 a(n) is the number of distinct values of the permanent of an n X n symmetric Toeplitz matrix using the integers 0 to n-1.
%H A369835 Wikipedia, <a href="http://en.wikipedia.org/wiki/Toeplitz_matrix">Toeplitz Matrix</a>.
%F A369835 a(n) <= A000142(n).
%t A369835 a[n_] := CountDistinct[Table[Permanent[ToeplitzMatrix[Part[Permutations[Join[{0}, Range[n - 1]]], i]]], {i, n !}]]; Join[{1}, Array[a,9]]
%o A369835 (Python)
%o A369835 from itertools import permutations
%o A369835 from sympy import Matrix
%o A369835 def A369835(n): return len({Matrix([p[i:0:-1]+p[:n-i] for i in range(n)]).per() for p in permutations(range(n))}) # _Chai Wah Wu_, Feb 11 2024
%Y A369835 Cf. A000142, A358326, A358327.
%Y A369835 Cf. A369830, A369831, A369832, A369833, A369834.
%K A369835 nonn,hard,more
%O A369835 0,4
%A A369835 _Stefano Spezia_, Feb 03 2024