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 A350937 #31 Dec 22 2023 16:35:54 %S A350937 1,1,7,89,2287,89025,5141775,404316249 %N A350937 Minimal permanent of an n X n Toeplitz matrix using the integers 1 to 2*n - 1. %C A350937 At least up to a(7) the minimal permanent is attained by a matrix which has 1, 3, 5, ... as first row and 1, 2, 4, 6,... as first column. - _Giovanni Resta_, Oct 13 2022 %C A350937 Also minimal permanent of an n X n Hankel matrix using the integers 1 to 2*n - 1. - _Stefano Spezia_, Dec 22 2023 %H A350937 Lucas A. Brown, <a href="https://github.com/lucasaugustus/oeis/blob/main/A350937%2B8.sage">A350937+8.sage</a> %H A350937 Wikipedia, <a href="http://en.wikipedia.org/wiki/Toeplitz_matrix">Toeplitz Matrix</a> %e A350937 a(2) = 7: %e A350937 1 2 %e A350937 3 1 %e A350937 a(3) = 89: %e A350937 1 2 4 %e A350937 3 1 2 %e A350937 5 3 1 %o A350937 (Python) %o A350937 from itertools import permutations %o A350937 from sympy import Matrix %o A350937 def A350937(n): return 1 if n == 0 else min(Matrix([p[n-1-i:2*n-1-i] for i in range(n)]).per() for p in permutations(range(1,2*n))) # _Chai Wah Wu_, Jan 27 2022 %Y A350937 Cf. A322908, A323254, A350930, A350938 (maximal). %K A350937 nonn,hard,more %O A350937 0,3 %A A350937 _Stefano Spezia_, Jan 26 2022 %E A350937 a(5) from _Alois P. Heinz_, Jan 26 2022 %E A350937 a(6) from _Lucas A. Brown_, Sep 04 2022 %E A350937 a(7) from _Giovanni Resta_, Oct 13 2022