Square, n = 16 record

A = 7341
= 0.0205278592375366568914956011730205278592375367…
64 triangles tie for the minimal area.

Symmetry

180° Rotationally symmetric (group C2, order 2).

16 points in 8 orbits (2 + 2 + 2 + 2 + 2 + 2 + 2 + 2) — hover a point to see its orbit.

Tesseract structure

This configuration is an affine image of the 16 vertices of the 4-dimensional hypercube. The animation rotates the tesseract, freezes a projection, stretches it into the optimal Heilbronn placement, then reveals the 64 minimal triangles grouped by parallelogram face.

About the structure

The 16 points have rational coordinates (denominators 31 and 33), 180-degree rotational symmetry, and exactly 64 triangles tied at area 7/341. Eight axis-aligned tesseract faces each contain 4 minimal triangles; six diagonal parallelograms contribute the remaining 24 among the 64.

Minimal triangles

64 triangles tied (within relative 10−9) at the minimal area, in 15 congruence classes:

countside lengthstriangles (point indices)
8 0.3098 · 0.3395 · 0.6364 (0,4,15) (1,5,14) (2,9,12) (3,8,13) (4,7,15) (5,6,14) (8,10,13) (9,11,12)
8 0.2651 · 0.4237 · 0.6774 (0,2,10) (1,3,11) (2,6,10) (3,7,11) (4,8,12) (5,9,13) (8,12,14) (9,13,15)
8 0.2651 · 0.6774 · 0.9374 (0,2,6) (0,6,10) (1,3,7) (1,7,11) (4,8,14) (4,12,14) (5,9,15) (5,13,15)
8 0.3098 · 0.6364 · 0.9416 (0,4,7) (0,7,15) (1,5,6) (1,6,14) (2,9,11) (2,11,12) (3,8,10) (3,10,13)
4 0.3098 · 0.3344 · 0.6309 (6,9,14) (7,8,15) (8,10,15) (9,11,14)
4 0.2651 · 0.4297 · 0.6837 (0,10,12) (1,11,13) (10,12,14) (11,13,15)
4 0.3395 · 0.4119 · 0.7432 (0,8,13) (1,9,12) (2,5,14) (3,4,15)
4 0.3098 · 0.6309 · 0.9361 (6,9,11) (6,11,14) (7,8,10) (7,10,15)
4 0.2651 · 0.6837 · 0.9438 (0,10,14) (0,12,14) (1,11,15) (1,13,15)
2 0.2651 · 0.5554 · 0.8134 (4,8,9) (5,8,9)
2 0.4035 · 0.5302 · 0.9294 (6,12,13) (7,12,13)
2 0.2651 · 0.8134 · 1.0748 (4,5,8) (4,5,9)
2 0.4035 · 0.6977 · 1.0985 (6,12,15) (7,13,14)
2 0.4119 · 0.7123 · 1.1217 (0,8,11) (1,9,10)
2 0.4035 · 0.9294 · 1.3313 (6,7,12) (6,7,13)

Provenance

Downloads

References