A114563 Number of "escalator" lattices in dimension n.

1, 1, 2, 9, 207, 1632, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset

0,3

References

Manjul Bhargava, lecture on Universal Forms, AMS Annual Meeting, Phoenix, AZ, Jan 08 2004.

Links

Table of n, a(n) for n=0..96.

Manjul Bhargava , On the Conway-Schneeberger fifteen theorem, pp. 27-38, in: Quadratic Forms and Their Applications, 1999.

Formula

Zero for n >= 6.

Crossrefs

Sequence in context: A367901 A069649 A111832 * A217017 A112311 A067564

Adjacent sequences: A114560 A114561 A114562 * A114564 A114565 A114566

Keyword

nonn,easy

Author

N. J. A. Sloane, Feb 16 2006

Status

approved