|View static image|
|Number of cells||1462|
|Discovered by||Dean Hickerson|
|Year of discovery||1992|
Sawtooth 1846 is an orthogonal sawtooth with expansion factor 25 that was found by Dean Hickerson on August 26, 1992. Its population in generations t near 30(25n) is about 59t/225 if t is odd, about 7t/10 if t is even but not equal to 46 (mod 60), and about 211t/900 if t = 46 (mod 60). However, the population in generation 6(25n) - 1125 (n ≥ 2) is only 1846. Slightly more specifically, the population in generation t = 30(25n) - 525 (n ≥ 1) is 59t/225 + 1951.
A shotgun produces a salvo of 4 eastward lightweight spaceships every 120 generations. Some are deleted; the others eventually catch up to a pair of unnamed c/3 orthogonal spaceships (see 60P3H1V0.3) and reflect off the their backs, forming westward middleweight spaceships. When a middleweight spaceship returns to the shotgun, it causes the deletion of 5 salvos. Notice the unusual eating of a pi-heptomino by two blocks that is used in this deletion). As a result of this reaction, the region between the shotgun and the spaceships alternately becomes full of spaceships and empty.
The c/3 spaceships were found by David Bell, who suggested this way of making a sawtooth.
The number of alive cells plotted versus the number of elapsed generations roughly forms an ever-increasing sawtooth graph.