A359521 Number of free mature snake polyominoes of n cells, where mature means that the snake cannot grow in either direction.

4, 0, 26, 0, 194, 17, 1086, 152, 6140, 1006, 32713, 6335, 172379, 38800

Offset: 15

Author

John Mason, Jan 05 2023

Keywords

• nonn
• more

Examples

			a(15) = 4 because of:
OOO   OOO   OOO   OOO
O O   O O   O O   O O
O  OO O  OO O  OO OO OO
O   O OO  O OOO O  OO O
OOOOO  OOOO   OOO   OOO
		

Crossrefs

Cf. A002013.