0,3

For the connection with A160720 (the "outward" version of the Ulam-Warburton cellular automaton A147562) see formula section and A267700.

A266533 (the first differences) gives the number of Y-toothpicks added to the structure at n-th stage.

First differs from A160120 at a(9).

First differs from A160715 at a(13).

Table of n, a(n) for n=0..67.

David Applegate, The movie version

N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS

Index entries for sequences related to cellular automata

Index entries for sequences related to toothpick sequences

Conjecture: a(n) = 1 + 3*(A160720(n) - 1)/4 = 1 + 3*A267700(n-1), n >= 1. This formula is correct! - N. J. A. Sloane, Jan 23 2016

a(n) = 1 + 3*(A159912(n) - n)/2, n >= 1. - Omar E. Pol, Jan 24 2016

Cf. A139250, A147562, A159912, A160120, A160715, A160720, A266533, A267700, A267701.

Sequence in context: A059014 A255650 A166700 * A160715 A160120 A130665

Adjacent sequences: A266529 A266530 A266531 * A266533 A266534 A266535

nonn

David Applegate and Omar E. Pol, Jan 18 2016

approved