A266533 First differences of A266532.

1, 3, 3, 9, 3, 9, 9, 21, 3, 9, 9, 21, 9, 21, 21, 45, 3, 9, 9, 21, 9, 21, 21, 45, 9, 21, 21, 45, 21, 45, 45, 93, 3, 9, 9, 21, 9, 21, 21, 45, 9, 21, 21, 45, 21, 45, 45, 93, 9, 21, 21, 45, 21, 45, 45, 93, 21, 45, 45, 93, 45, 93, 93, 189, 3, 9, 9, 21, 9, 21, 21, 45, 9, 21, 21, 45, 21, 45, 45, 93

Offset

1,2

Comments

Number of Y-toothpicks added at n-th stage in the structure of A266532.

A simplified version of A160121.

Links

Table of n, a(n) for n=1..80.

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

Formula

a(1) = 1. It appears that a(n) = 3*A038573(n-1), n >= 2.

Example

Written as an irregular triangle in which the row lengths are the terms of A011782 the sequence begins:
1;
3;
3, 9;
3, 9, 9, 21;
3, 9, 9, 21, 9, 21, 21, 45;
3, 9, 9, 21, 9, 21, 21, 45, 9, 21, 21, 45, 21, 45, 45, 93;
...
Observation: at least the first 11 terms of the right border coincide with A068156.

Crossrefs

Cf. A000120, A011782, A038573, A068156. A139251, A147582, A160121, A151710, A160721, A266532, A267701.

Sequence in context: A145444 A165824 A256689 * A151710 A160121 A048883

Adjacent sequences: A266530 A266531 A266532 * A266534 A266535 A266536

Keyword

nonn,tabf

Author

David Applegate and Omar E. Pol, Jan 18 2016

Status

approved