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A204261
Permanent of the n-th principal submatrix of A204260.
2
1, 2, 13, 104, 1357, 22052, 555325, 17622590, 680239111, 31511481788, 1717710101869, 109014509616567, 8596454332733239, 783330147715515842, 79369033657791374935, 9105430313767018411610
OFFSET
1,2
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 *)
CROSSREFS
Cf. A204260.
Sequence in context: A378517 A371583 A083062 * A371586 A371574 A127746
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 14 2012
STATUS
approved