A204266 Permanent of the n-th principal submatrix of A204123.

1, 5, 27, 252, 2369, 36103, 518000, 9756177, 200951191, 4899768134, 113249415026, 3553351288210, 105127854228522, 3433390910771142, 122658122808278570, 4957371400718135098, 191264018429152335168, 8676487463037943766552, 377433133681960165450048, 18780210971968950831128080

Offset: 1

Author

Clark Kimberling, Jan 14 2012

Keywords

• nonn

Crossrefs

Cf. A204123.

Programs

Mathematica

f[i_, j_] := Floor[Max[i, j]/Min[i, j]];
m[n_] := Table[f[i, j], {i, 1, n}, {j, 1, n}]
TableForm[m[8]] (* 8x8 principal submatrix *)
Flatten[Table[f[i, n + 1 - i],
  {n, 1, 12}, {i, 1, n}]]  (*  A204123 *)
Permanent[m_] :=
  With[{a = Array[x, Length[m]]},
   Coefficient[Times @@ (m.a), Times @@ a]];
Table[Permanent[m[n]], {n, 1, 14}]  (* A204266 *)

Extensions

a(18)-a(20) from Pontus von Brömssen, Mar 03 2024