A204437 Symmetric matrix: f(i,j)=((i+j+1)^2 mod 3), by (constant) antidiagonals.

0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1

Offset

1

Comments

A block matrix over {0,1}. For guides to related matrices and permanents, see A204435 and A204263.

Links

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

Example

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

Mathematica

f[i_, j_] := Mod[(1 + 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}]]         (* A204437 *)
Permanent[m_] :=
  With[{a = Array[x, Length[m]]},
   Coefficient[Times @@ (m.a), Times @@ a]];
Table[Permanent[m[n]], {n, 1, 22}]   (* A204438 *)

Crossrefs

Cf. A204438, A204435.

Sequence in context: A204549 A112713 A143536 * A080110 A286419 A257799

Adjacent sequences: A204434 A204435 A204436 * A204438 A204439 A204440

Keyword

nonn,tabl

Author

Clark Kimberling, Jan 15 2012

Status

approved