OFFSET
0,2
COMMENTS
This is also the negative of the (1,2) element of the product matrix after multiplying the unit matrix from the
left by the matrices (0,-2;j-1,4j-4) in the order j=2 to n.
MATHEMATICA
M[n_] := {{0, -2}, {(n - 1), 4*(n - 1)}} v[1] = {0, 1} v[n_] := v[n] = M[n].v[n - 1] a = Table[Abs[v[n][[1]]], {n, 1, 25}]
RecurrenceTable[{a[0]==0, a[1]==2, a[n]==4(n-1)a[n-1]-2(n-1)a[n-2]}, a, {n, 20}] (* Harvey P. Dale, Apr 11 2020 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, Jun 15 2005
EXTENSIONS
Definition replaced by recurrence by the Associate Editors of the OEIS, Sep 28 2009
STATUS
approved