A204421 Symmetric matrix: f(i,j)=(i+j+2 mod 3), by antidiagonals.

1, 2, 2, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2

Offset

1,2

Comments

A block matrix over {0,1,2}. See A204263 for a guide to related matrices and permanents.

Links

Table of n, a(n) for n=1..99.

Example

Northwest corner:
1 2 0 1 2 0
2 0 1 2 0 1
0 1 2 0 1 2
1 2 0 1 2 0
2 0 1 2 0 1
0 1 2 0 1 2

Mathematica

f[i_, j_] := Mod[i + j + 2, 3];
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}]]    (* A204421 *)
Permanent[m_] :=
  With[{a = Array[x, Length[m]]},
   Coefficient[Times @@ (m.a), Times @@ a]];
Table[Permanent[m[n]], {n, 1, 22}]  (* A179079 *)

Crossrefs

Cf. A179079, A204263.

Sequence in context: A180823 A049800 A281082 * A131018 A300067 A035395

Adjacent sequences: A204418 A204419 A204420 * A204422 A204423 A204424

Keyword

nonn,tabl

Author

Clark Kimberling, Jan 15 2012

Status

approved