A005426 Number of linear geometries on n points with <= 3 points per line. (Formerly M0292)

1, 1, 1, 2, 2, 3, 5, 11, 32, 163, 1680

Offset

0,4

References

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=0..10.

D. G. Glynn, Rings of geometries II, J. Combin. Theory, A 49 (1988), 26-66.

Crossrefs

Sequence in context: A078445 A127166 A103596 * A014644 A089541 A065843

Adjacent sequences: A005423 A005424 A005425 * A005427 A005428 A005429

Keyword

nonn,hard,nice

Author

N. J. A. Sloane, Simon Plouffe

Status

approved