A204237 Symmetric matrix given by f(i,j)=max(3i-j,3j-i).

2, 5, 5, 8, 4, 8, 11, 7, 7, 11, 14, 10, 6, 10, 14, 17, 13, 9, 9, 13, 17, 20, 16, 12, 8, 12, 16, 20, 23, 19, 15, 11, 11, 15, 19, 23, 26, 22, 18, 14, 10, 14, 18, 22, 26, 29, 25, 21, 17, 13, 13, 17, 21, 25, 29, 32, 28, 24, 20, 16, 12, 16, 20, 24, 28, 32, 35, 31, 27, 23

Offset: 1

Author

Clark Kimberling, Jan 13 2012

Keywords

• nonn
• tabl

Examples

			Northwest corner:
2....5....8....11...14...17
5....4....7....10...13...16
8....7....6....9....12...15
11...10...9....8....11...14
14...13...12...11...10...13
		

Crossrefs

Cf. A204238, A204239.

Programs

Mathematica

f[i_, j_] := Max[3 i - j, 3 j - i];
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}]]  (* A204237 *)
Table[Det[m[n]], {n, 1, 22}]  (* A204238 *)
Permanent[m_] :=
  With[{a = Array[x, Length[m]]},
   Coefficient[Times @@ (m.a), Times @@ a]];
Table[Permanent[m[n]], {n, 1, 14}] (* A204239 *)