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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A323382 a(n) is the period of the oscillating pattern formed by a diagonal line of 2*n cells in the Life-like cellular automaton B2e3ijkn4cz5/S236.

Original entry on oeis.org

2, 3, 2, 5, 8, 3, 20, 14, 26, 3, 36, 5, 106, 3, 14, 29, 48, 3, 80, 67, 156, 3, 74, 14, 594, 3, 26, 93, 440, 3, 380, 115, 1062, 3, 1826, 82, 1864, 3, 1488, 2603, 328, 3, 1714, 10229, 2330, 3, 1372, 23, 15202, 3, 43186, 7524, 49534, 3, 69612, 9508, 5112, 3, 1260, 54687
Offset: 1

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Author

WG Zeist, Jan 12 2019

Keywords

Comments

An explanation of the Hensel notation used to define the cellular automaton rule can be found on the LifeWiki (see links).
Lines of odd lengths are excluded because they break up into patterns not consisting of diagonal lines.
These diagonal line oscillators are effectively emulating a four-state one-dimensional cellular automaton.
From Charlie Neder, Feb 12 2019: (Start)
Specifically, such an oscillator with 2*n cells is isomorphic to a row of 2*n state-1 cells that evolve according to the following rules:
1) A state-1 cell becomes state-3 if it has a state-1 neighbor, and state-2 otherwise,
2) A state-2 cell becomes state-1 unconditionally,
3) A state-3 cell becomes state-1 if both its neighbors are state-3, and state-2 otherwise. (End)

Examples

			a(4) = 5 because a diagonal line of 8 cells oscillates with period 5 in this cellular automaton.
		

Formula

If n == 2 (mod 4), a(n) = 3.