A184408 Number of holes in the toothpick structure of A182840.

0, 0, 0, 0, 0, 0, 0, 2, 6, 6, 6, 6, 6, 8, 12, 18, 30, 30, 30, 30, 30, 30, 30, 34, 46, 56, 60, 60, 60, 66, 80, 98, 126, 126, 126, 126, 126, 126, 126, 130, 142, 150, 150, 150, 150, 154, 166, 186, 222, 248, 252, 252, 252, 252, 252, 260, 288, 322, 344, 348, 348, 364, 404, 450, 510, 510, 510, 510, 510, 510, 510, 514, 526

Offset: 0

Author

Olaf Voß, Jan 13 2011

Keywords

• nonn

Comments

Each connected group of unoccupied lines in the hexagonal structure enclosed by toothpicks counts as a hole.

Examples

			Structure after step 8:
      \_/
    \_/ \_/
  \_/ \_/ \_/
\_/  _/ \_  \_/
/ \_/ \_/ \_/ \
\_/ \_/ \_/ \_/
/ \ / \_/ \ / \
\_/ \_/ \_/ \_/
/ \_/ \_/ \_/ \
\_/ \_/ \_/ \_/
/ \_  \_/  _/ \
  / \_/ \_/ \
    / \_/ \
      / \
There are 6 holes in this structure, so a(8)=6.
		

Links

• Olaf Voß, Table of n, a(n) for n = 0..625
• N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS
• Olaf Voß, Toothpick structures on hexagonal net
• Index entries for sequences related to toothpick sequences

Crossrefs

For total number of missing toothpicks see A184409.