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 A374619 #6 Jul 15 2024 10:20:16 %S A374619 1,1,1,2,6,22,120,717,5039,40312,362874 %N A374619 a(n) is the number of distinct values of the determinant of an n X n symmetric Toeplitz matrix having 1 on the main diagonal and all the first n-1 primes off-diagonal. %H A374619 Wikipedia, <a href="http://en.wikipedia.org/wiki/Toeplitz_matrix">Toeplitz Matrix</a>. %F A374619 a(n) <= (n-1)! for n > 0. %t A374619 a[n_]:=CountDistinct[Table[Det[ToeplitzMatrix[Join[{1},Part[Permutations[Prime[Range[n-1]]], i]]]], {i, (n -1)!}]]; Join[{1}, Array[a, 10]] %Y A374619 Cf. A000142, A369832. %Y A374619 Cf. A374340, A374341, A374342, A374343. %Y A374619 Cf. A374617, A374618, A374620, A374621. %K A374619 nonn,hard,more %O A374619 0,4 %A A374619 _Stefano Spezia_, Jul 14 2024