A137193 Number of n-celled polyhexes with perimeter < 4n+2.

0, 0, 1, 2, 10, 46, 215, 1037, 5083, 24918, 122437

Offset: 1

Author

Tanya Khovanova, Mar 03 2008

Keywords

• hard
• more
• nonn

Comments

These are n-cell polyhexes with the perimeter less than the maximum possible one.

If we associate a graph to a polyhex with vertices representing cells and edges representing two cells with a common edge, then this sequence enumerates polyhexes whose corresponding graphs have cycles.

Formula

A000228(n)-A038142(n)