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 A204266 #10 Mar 03 2024 12:44:20
%S A204266 1,5,27,252,2369,36103,518000,9756177,200951191,4899768134,
%T A204266 113249415026,3553351288210,105127854228522,3433390910771142,
%U A204266 122658122808278570,4957371400718135098,191264018429152335168,8676487463037943766552,377433133681960165450048,18780210971968950831128080
%N A204266 Permanent of the n-th principal submatrix of A204123.
%t A204266 f[i_, j_] := Floor[Max[i, j]/Min[i, j]];
%t A204266 m[n_] := Table[f[i, j], {i, 1, n}, {j, 1, n}]
%t A204266 TableForm[m[8]] (* 8x8 principal submatrix *)
%t A204266 Flatten[Table[f[i, n + 1 - i],
%t A204266 {n, 1, 12}, {i, 1, n}]] (* A204123 *)
%t A204266 Permanent[m_] :=
%t A204266 With[{a = Array[x, Length[m]]},
%t A204266 Coefficient[Times @@ (m.a), Times @@ a]];
%t A204266 Table[Permanent[m[n]], {n, 1, 14}] (* A204266 *)
%Y A204266 Cf. A204123.
%K A204266 nonn
%O A204266 1,2
%A A204266 _Clark Kimberling_, Jan 14 2012
%E A204266 a(18)-a(20) from _Pontus von Brömssen_, Mar 03 2024