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

1,2

Links

Table of n, a(n) for n=1..20.

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 *)

Crossrefs

Cf. A204123.

Sequence in context: A356538 A342904 A230563 * A266204 A360770 A360726

Adjacent sequences: A204263 A204264 A204265 * A204267 A204268 A204269

Keyword

nonn

Author

Clark Kimberling, Jan 14 2012

Extensions

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

Status

approved