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A307783
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The permanent of an n X n symmetric Toeplitz matrix M(n) whose first row consists of n, n-1, ..., 1.
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6
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1, 5, 62, 1472, 57228, 3300052, 264163120, 28004426240, 3796084024832, 640290996560896, 131495036625989504, 32300689159458652160, 9350873610168606862080, 3150550820854335942423808, 1222211647879605626853439488, 540858935979668390014623285248, 270804098518125729769134021574656
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OFFSET
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1,2
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COMMENTS
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The matrix M(n) differs from that of A204235 in using for the first row the positive integers 1, 2,..., n in decreasing order in place of in increasing order (see examples).
The trace of the matrix M(n) is A000290(n).
The determinant of the matrix M(n) is A001792(n-1).
The sum of the k-th row of the matrix M(n) is A008867(n,k).
For n > k, the sum of the k-diagonal of the matrix M(n) is A055461(n,k).
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LINKS
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EXAMPLE
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For n = 1 the matrix M(1) is
1
with permanent a(1) = 1.
For n = 2 the matrix M(2) is
2, 1
1, 2
with permanent a(2) = 5.
For n = 3 the matrix M(3) is
3, 2, 1
2, 3, 2
1, 2, 3
with permanent a(3) = 62.
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MAPLE
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f:= proc(n) uses LinearAlgebra; Permanent(ToeplitzMatrix([i, i=n..1, -1)])) end proc: map(f, [$1..17]);
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MATHEMATICA
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b[i_]:=i; a[n_]:=Permanent[ToeplitzMatrix[Reverse[Array[b, n]], Reverse[Array[b, n ]]]]; Array[a, 17]
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PROG
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(PARI) {a(n) = matpermanent(matrix(n, n, i, j, n + 1 - max(i - j + 1, j - i + 1)))}
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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