0

Row n has length 2n+1.

Robert Price, Table of n, a(n) for n = 0..10000

Eric Weisstein's World of Mathematics, Elementary Cellular Automaton

Stephen Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.

The first ten rows:

1

1 0 1

0 0 1 1 0

1 1 1 1 0 1 1

0 0 0 0 0 1 1 0 0

1 1 1 1 1 1 1 0 1 1 1

0 0 0 0 0 0 0 0 1 1 0 0 0

1 1 1 1 1 1 1 1 1 1 0 1 1 1 1

0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0

1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1

Pattern of the full writeup, including leading and trailing 0's and 1's:

00000000000000100000000000000

11111111111111011111111111111

00000000000000110000000000000

11111111111111101111111111111

00000000000000011000000000000

11111111111111110111111111111

00000000000000001100000000000

11111111111111111011111111111

00000000000000000110000000000

11111111111111111101111111111

00000000000000000011000000000

11111111111111111110111111111

00000000000000000001100000000

11111111111111111111011111111

- R. J. Mathar, Aug 07 2025

rule=59; rows=20; ca=CellularAutomaton[rule, {{1}, 0}, rows-1, {All, All}]; (* Start with single black cell *) catri=Table[Take[ca[[k]], {rows-k+1, rows+k-1}], {k, 1, rows}]; (* Truncated list of each row *) Flatten[catri] (* Triangle Representation of CA *)

Cf. A266717, A266718, A266719 (middle column), A267269 (rows reversed).

Cf. A266722, A266723, A266724, A266725.

Sequence in context: A164057 A140820 A275661 * A190242 A167501 A285533

Adjacent sequences: A266713 A266714 A266715 * A266717 A266718 A266719

nonn,tabf,easy

Robert Price, Jan 03 2016

approved