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A278925
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a(n) = permanent M_n where M_n is the n X n matrix m(i,j) = i^3 + j^3.
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4
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1, 2, 113, 38736, 46311652, 143820883800, 966462062838180, 12412328008727861760, 278484670746890475310656, 10197331743850942940587152000, 577793817845799602600135280168000, 48534819511412868687827815575204633600, 5834998526939444017550860154062183732711680
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) ~ c * d^n * n!^4 / n^(3/2), where d = 6.538385468679... and c = 0.84959670006...
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MAPLE
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with(LinearAlgebra):
a:= n-> `if`(n=0, 1, Permanent(Matrix(n, (i, j)-> i^3+j^3))):
seq(a(n), n=0..16);
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MATHEMATICA
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Flatten[{1, Table[Permanent[Table[i^3+j^3, {i, 1, n}, {j, 1, n}]], {n, 1, 15}]}]
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PROG
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(PARI) {a(n) = matpermanent(matrix(n, n, i, j, i^3+j^3))}
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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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