

A108208


a(n) = 4*(n1)*a(n1) 2*(n1)*a(n2), with a(0)=0, a(1)=2.


0



0, 2, 8, 56, 624, 9536, 184480, 4313088, 118183744, 3712870400, 131536027008, 5187183672320, 225342288987904, 10691937463283712, 550121848577067520, 30507449271343837184, 1813943300823318205440, 115116132876009362358272
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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;j1,4j4) in the order j=2 to n.


LINKS

Table of n, a(n) for n=0..17.


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}]


CROSSREFS

Cf. A000166.
Sequence in context: A197949 A005439 A128814 * A203199 A135079 A084872
Adjacent sequences: A108205 A108206 A108207 * A108209 A108210 A108211


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



