Error in A115866

[Max Alekseyev]

On 3/2/07, Nick Hobson <nickh at qbyte.org> wrote:

> I believe the sequence should begin: 1, 13, 409, 16081, 699121, 32193253.
> If someone can confirm these terms, I will submit a correction.

I concur. The first 21 terms are (for n=0..20):

1, 13, 409, 16081, 699121, 32193253, 1538743249, 75494983297,
3776339263873, 191731486403293, 9850349744182729, 510958871182549297,
26716694098174738321, 1406361374518034383189, 74456543501901550262689,
3961518532003397434536961, 211689479080817606497324033,
11355093839222763705129084589, 611152040584076639660629371001,
32992715293059931135426553471761, 1785928841771860542254045576118961

a(n) can be computed as the coefficient of (xyz)^n in the expansion of
1 / (1-x-y-z-xy-xz-yz-xyz)

Max