A359521 - OEIS

%I #7 Jan 05 2023 11:04:34

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

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

%e a(15) = 4 because of:

%e OOO   OOO   OOO   OOO

%e O O   O O   O O   O O

%e O  OO O  OO O  OO OO OO

%e O   O OO  O OOO O  OO O

%e OOOOO  OOOO   OOO   OOO

%Y Cf. A002013.

%K nonn,more

%O 15,1

%A _John Mason_, Jan 05 2023