A204430 Permanent of the n-th principal submatrix of A204429.

1, 2, 9, 34, 144, 1032, 6936, 48816, 530712, 5005152, 50015232, 707802624, 8714718720, 112586112000, 1938416832000, 29588291712000, 469224244224000, 9509523337728000, 173318541516288000, 3261008730405888000

Offset: 1

Author

Clark Kimberling, Jan 15 2012

Keywords

• nonn

Crossrefs

Cf. A204229, A204263.

Programs

Mathematica

f[i_, j_] := Mod[2 i + 2 j, 3];  (* symmetric *)
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, 14}, {i, 1, n}]]        (* A204429 *)
Permanent[m_] :=
  With[{a = Array[x, Length[m]]},
   Coefficient[Times @@ (m.a), Times @@ a]];
Table[Permanent[m[n]], {n, 1, 22}]   (* A204430 *)