A204261 Permanent of the n-th principal submatrix of A204260.

1, 2, 13, 104, 1357, 22052, 555325, 17622590, 680239111, 31511481788, 1717710101869, 109014509616567, 8596454332733239, 783330147715515842, 79369033657791374935, 9105430313767018411610

Offset: 1

Author

Clark Kimberling, Jan 14 2012

Keywords

• nonn

Crossrefs

Cf. A204260.

Programs

Mathematica

f[i_, j_] := Ceiling[i*j/(i + j)];
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}]]  (* A204260 *)
Permanent[m_] :=
  With[{a = Array[x, Length[m]]},
   Coefficient[Times @@ (m.a), Times @@ a]];
Table[Permanent[m[n]], {n, 1, 14}]  (* A204261 *)