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 A204267 Symmetric matrix: f(i,j)=(i+j+1 mod 3), by antidiagonals. 3
 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 (list; table; graph; refs; listen; history; text; internal format)
 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

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Last modified January 17 16:41 EST 2021. Contains 340247 sequences. (Running on oeis4.)