A244021
Analog of A244020, but starting with 5 points instead of 4.
Original entry on oeis.org
5, 10, 15, 90, 3495
Offset: 1
A244023
Analog of A244020, but starting with 6 points instead of 4.
Original entry on oeis.org
6, 15, 45, 855, 342000
Offset: 1
A244025
Analog of A244020, but starting with 5 points, and with the constraint that new points (or lines) are formed only from the intersections of lines (or points) of the same generation.
Original entry on oeis.org
5, 10, 15, 75, 2080
Offset: 1
A140468
Number of points at the n-th step of the following iteration, starting with four points in general position in the real projective plane: dualize the current pointset to a family of lines, take all intersections of those lines, repeat.
Original entry on oeis.org
4, 6, 7, 9, 13, 25, 97, 1741, 719725
Offset: 1
Joshua Cooper (cooper(AT)math.sc.edu), Jun 28 2008
a(2)=6 because four points in general position define six lines.
- K. Bezdek and J. Pach, A point set everywhere dense in the plane, Elem. Math. 40 (4) (1985) 81--84.
- Joshua Cooper, Mark Walters, Iterated point-line configurations grow doubly-exponentially, Discrete Comput. Geom. 43 (2010), no. 3, 554-562. MR2587837 (2011f:51016) 51M04 (52C35).
- Shalosh B. Ekhad, Doron Zeilberger, Enumerative Geometrical Genealogy (Or: The Sex Life of Points and Lines), arXiv:1406.5157 [math.CO], (19-June-2014)
- D. Ismailescu and R. Radoicic, A dense planar point set from iterated line intersections Comput. Geom. 27 (2004), no. 3, 257-267.
A244026
Analog of A140468, but starting with 5 points, and with the constraint that new points (or lines) are formed only from the intersections of lines (or points) of the same generation.
Original entry on oeis.org
5, 10, 20, 85, 2100
Offset: 1
A244022
Analog of A140468, but starting with 5 points instead of 4.
Original entry on oeis.org
5, 10, 20, 100, 3515
Offset: 1
A244024
Analog of A140468, but starting with 6 points instead of 4.
Original entry on oeis.org
6, 15, 51, 870, 342051
Offset: 1
Showing 1-7 of 7 results.