A091910 Number of distinct distances between the intersection points in A091908 measured from the center of the equilateral triangle.

1, 3, 4, 10, 11, 21, 20, 36, 36, 55, 56, 78, 79, 103, 103, 136, 135, 171, 169, 209, 211, 253, 243, 300, 301, 350, 351, 404, 403, 463, 460, 524, 526, 586, 590, 664, 664, 736, 731, 818, 811, 899, 898, 968, 990, 1074, 1047, 1167, 1164, 1265, 1265, 1362, 1368

Offset

2,2

Comments

Terms group into pairs via the plot, yielding two curves. - Bill McEachen, Sep 17 2025

Links

Table of n, a(n) for n=2..54.

Hugo Pfoertner, Visualization of diagonal intersections in an equilateral triangle.

Hugo Pfoertner, Diagonal intersections in an equilateral triangle. Program and results.

Example

a(2)=1: The 3 line segments intersect each other at the triangle center (r=0).
a(3)=3: There are 3 intersection points at r=0.2, 3 at r=0.25 and 6 at r=0.3779645, i.e. 3 different radii. See pictures given at link.

Prog

(Fortran) ! Program given at link.

Crossrefs

Cf. A091908, A092098.

Sequence in context: A200816 A327300 A047341 * A131179 A079353 A242654

Adjacent sequences: A091907 A091908 A091909 * A091911 A091912 A091913

Keyword

more,nonn

Author

Hugo Pfoertner, Feb 19 2004

Extensions

Extended by Bill McEachen, Sep 17 2025

Status

approved