A182981 Number of grid point that are covered at the n-th stage of the cellular automata which is a version "forest" of the shell model of partitions, with a(0)=1. The outers shells are represented as trees.

1, 3, 5, 7, 13, 17, 31, 39

Offset: 0

Author

Omar E. Pol, Jan 26 2011

Keywords

• nonn

Comments

It appears that the version of the shell model of partitions which gives this sequence also shows a connection between the partition theory and the graph theory because the structure looks like a forest in which each last section is a tree. In a three-dimensional version of the structure we can see that one of the views shows the branches of the trees of the even numbers tilted 45 degrees to the left and the branches of the trees of the odd numbers tilted 45 degrees to the right. Another view contains the "roots" of trees, the tables of both A182982 and A182983.

Crossrefs

Cf. A135010, A182718, A182982, A182983.