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A108205
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a(n) = 2*(n-1)*a(n-1)+(n-1)*a(n-2) with a(0)=0, a(1)=1.
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0
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0, 1, 2, 10, 66, 568, 6010, 75528, 1099462, 18195616, 337416246, 6930281080, 156177762466, 3831429672144, 101647482387802, 2899769522268472, 88517797903871190, 2878965845280173632, 99389641303891713718
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OFFSET
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0,3
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COMMENTS
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This is also the (2,2) element of the product matrix after multiplying the unit matrix from the left by the matrices (0,1;j-1,2j-2) in the order j=2 to n.
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LINKS
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MATHEMATICA
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M[n_] := {{0, 1}, {(n - 1), 2*(n - 1)}} v[1] = {0, 1} v[n_] := v[n] = M[n].v[n - 1] a = Table[Abs[v[n][[1]]], {n, 1, 25}]
nxt[{n_, a_, b_}]:={n+1, b, 2n*b+n*a}; NestList[nxt, {1, 0, 1}, 20][[;; , 2]] (* Harvey P. Dale, May 26 2023 *)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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Definition substituted by G. Detlefs' recurrence by the Associate Editors of the OEIS, Sep 28 2009
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STATUS
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approved
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