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A108205
a(n) = 2*(n-1)*a(n-1)+(n-1)*a(n-2) with a(0)=0, a(1)=1.
0
0, 1, 2, 10, 66, 568, 6010, 75528, 1099462, 18195616, 337416246, 6930281080, 156177762466, 3831429672144, 101647482387802, 2899769522268472, 88517797903871190, 2878965845280173632, 99389641303891713718
OFFSET
0,3
COMMENTS
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.
MATHEMATICA
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 *)
CROSSREFS
Cf. A000166.
Sequence in context: A376226 A346417 A377529 * A228938 A245000 A108397
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, Jun 15 2005
EXTENSIONS
Definition substituted by G. Detlefs' recurrence by the Associate Editors of the OEIS, Sep 28 2009
STATUS
approved