OFFSET

1,1

COMMENTS

EXAMPLE

Northwest corner:

3...4...5....6....7....8

4...6...7....8....9....10

5...7...9....10...11...12

6...8...10...12...13...14

MATHEMATICA

f[i_, j_] := Min[2 i + j, 2 j + i];

m[n_] := Table[f[i, j], {i, 1, n}, {j, 1, n}]

TableForm[m[6]] (* 6x6 principal submatrix *)

Flatten[Table[f[i, n + 1 - i],

{n, 1, 12}, {i, 1, n}]] (* A204002 *)

p[n_] := CharacteristicPolynomial[m[n], x];

c[n_] := CoefficientList[p[n], x]

TableForm[Flatten[Table[p[n], {n, 1, 10}]]]

Table[c[n], {n, 1, 12}]

Flatten[%] (* A204003 *)

TableForm[Table[c[n], {n, 1, 10}]]

CROSSREFS

KEYWORD

nonn,tabl

AUTHOR

Clark Kimberling, Jan 09 2012

STATUS

approved