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 A374345 #9 Jul 08 2024 08:38:33
%S A374345 1,1,5,59,2454,177998,36960008,7670953632,2822399976144,
%T A374345 1061085324952592,598646324654443008
%N A374345 a(n) is the maximal permanent of an n X n symmetric Toeplitz matrix having 1 on the main diagonal and all the first n-1 primes off-diagonal.
%H A374345 Wikipedia, <a href="https://en.wikipedia.org/wiki/Toeplitz_matrix">Toeplitz Matrix</a>.
%e A374345 a(5) = 177998:
%e A374345 [1, 7, 5, 3, 2]
%e A374345 [7, 1, 7, 5, 3]
%e A374345 [5, 7, 1, 7, 5]
%e A374345 [3, 5, 7, 1, 7]
%e A374345 [2, 3, 5, 7, 1]
%t A374345 a[n_]:=Max[Table[Permanent[ToeplitzMatrix[Join[{1},Part[Permutations[Prime[Range[n-1]]],i]]]],{i,(n-1)!}]]; Join[{1},Array[a,10]]
%Y A374345 Cf. A374067, A374278.
%Y A374345 Cf. A374340, A374341, A374342, A374343, A374067 (minimal).
%K A374345 nonn,hard,more
%O A374345 0,3
%A A374345 _Stefano Spezia_, Jul 05 2024