A204267 Symmetric matrix: f(i,j)=(i+j+1 mod 3), by antidiagonals.

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

Offset

1,4

Comments

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

Links

G. C. Greubel, Table of n, a(n) for the first 100 rows, flattened

Example

Northwest corner:
0 1 2 0 1 2
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

Mathematica

f[i_, j_] := Mod[i + j + 1, 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}]]    (* A204267 *)
Permanent[m_] :=
  With[{a = Array[x, Length[m]]},
   Coefficient[Times @@ (m.a), Times @@ a]];
Table[Permanent[m[n]], {n, 1, 22}]  (* A204268 *)

Crossrefs

Cf. A204268.

Sequence in context: A180472 A308583 A093315 * A237452 A132784 A180834

Adjacent sequences: A204264 A204265 A204266 * A204268 A204269 A204270

Keyword

nonn,tabl

Author

Clark Kimberling, Jan 15 2012

Status

approved