A350639 a(n) is the number of connected components in the set of cells added at stage n of the cellular automaton described in A350632.

0, 1, 1, 4, 1, 4, 4, 12, 1, 4, 4, 12, 4, 20, 12, 36, 9, 8, 4, 12, 4, 20, 12, 36, 12, 20, 20, 36, 28, 52, 36, 92, 25, 16, 4, 12, 4, 20, 12, 36, 12, 20, 20, 36, 28, 52, 36, 92, 28, 36, 28, 52, 36, 68, 44, 108, 52, 76, 76, 100, 84, 140, 92, 228, 89, 56, 4, 12, 4

Offset

0,4

Comments

We only consider cells turned ON at stage n (and that were OFF in prior stages).

Links

Table of n, a(n) for n=0..68.

Rémy Sigrist, C++ program for A350639

Index entries for sequences related to cellular automata

Example

The first 5 generations can be depicted as follows:
        +-------+                   +-------+
        | 5     |                   | 5     |
        |   +---+-------------------+---+   |
        |   | 4                         |   |
        +---+   +-------+---+-------+   +---+
            |   | 3     |   | 3     |   |
            |   |   +---+---+---+   |   |
            |   |   | 2         |   |   |
            |   +---+   +---+   +---+   |
            |   |   |   | 1 |   |   |   |
            |   +---+   +---+   +---+   |
            |   | 3 |           |   |   |
            |   |   +---+---+---+   |   |
            |   |       |   | 3     |   |
        +---+   +-------+---+-------+   +---+
        | 5 |                           |   |
        |   +---+-------------------+---+   |
        |       |                   | 5     |
        +-------+                   +-------+
- so a(0) = 0,
     a(1) = 1,
     a(2) = 1,
     a(3) = 4,
     a(4) = 1,
     a(5) = 4.

Prog

(C++) See Links section.

Crossrefs

Cf. A350632.

Sequence in context: A366887 A204714 A341100 * A347264 A328147 A151783

Adjacent sequences: A350636 A350637 A350638 * A350640 A350641 A350642

Keyword

nonn

Author

Rémy Sigrist, Jan 09 2022

Status

approved