I-heptomino is the name given by Conway to the heptomino shown in the infobox. After one generation, this converges to the same evolutionary sequence as the H-heptomino. The name I rather than H was chosen as standard for this sequence because conduits use one-letter names and H is the Herschel.
The longest-lasting active reaction is the standard evolutionary sequence of a Herschel, at the bottom of the pattern below:
x = 4, y = 4, rule = B3/S23
2o$bo$b2o$2b2o!
#C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]]
#C [[ HEIGHT 480 WIDTH 600 THUMBSIZE 2 ZOOM 20 GRID OFF GPS 10 AUTOSTART T 0 PAUSE 4 T 100 ZOOM 6 T 299 PAUSE 1 LOOP 300 ]]
In the following examples, on the top, there are two six-cell polyplets that follow the I-heptomino sequence. The one on the left becomes the I-heptomino itself, while the one on the right follows a slightly different sequence. On the bottom, there are two houses with one cell removed each; both follow the I-heptomino sequence.
The century sequence has a phase around generation 53 that is an I-heptomino sequence plus five stable objects (three blocks, a beehive, and a toad). The I sequence then hits the beehive, destroying the beehive and toad and leaving behind a blinker.
Hasslers
The I-heptomino sequence can be hassled in oscillators. Four examples are shown below. For all four, generation 4 is the pattern that the various predecessors in the I sequence typically converge to; this is done to show a variety of predecessors.
