A204257 Matrix given by f(i,j)=1+[(i+2j) mod 3], by antidiagonals.

1, 3, 2, 2, 1, 3, 1, 3, 2, 1, 3, 2, 1, 3, 2, 2, 1, 3, 2, 1, 3, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 2, 1, 3, 2, 1, 3, 2, 1, 3, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2, 1, 3, 2

Offset

1,2

Links

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

Example

Northwest corner:
1 3 2 1 3 2 1 3
2 1 3 2 1 3 2 1
3 2 1 3 2 1 3 2
1 3 2 1 3 2 1 3
2 1 3 2 1 3 2 1
3 2 1 3 2 1 3 2

Mathematica

f[i_, j_] := 1 + Mod[i + 2 j, 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, 12}, {i, 1, n}]]  (* A204257 *)
Permanent[m_] :=
  With[{a = Array[x, Length[m]]},
   Coefficient[Times @@ (m.a), Times @@ a]];
Table[Permanent[m[n]], {n, 1, 20}]  (* A204258 *)

Crossrefs

Cf. A204258.

Sequence in context: A088435 A328630 A171900 * A074976 A329873 A068448

Adjacent sequences: A204254 A204255 A204256 * A204258 A204259 A204260

Keyword

nonn,tabl

Author

Clark Kimberling, Jan 14 2012

Status

approved