%I #15 Nov 04 2022 11:32:57
%S 1,6,24,181,941,4662,23691,119271,603760,3050402,15428576,78004550,
%T 394462578,1994595585,10086050889,51001111356,257894037378,
%U 1304071170194,6594196094078,33344335235915,168609627579175,852594638783225,4311246376730011
%N Number of free polyominoes of width 3 and height n.
%C The sequence can be generated using a series of recursive formulas in a fashion similar to A353067. - _John Mason_, Nov 04 2022
%H John Mason, <a href="/A336267/b336267.txt">Table of n, a(n) for n = 1..400</a>
%e a(2)=6, bounding box 2 X 3 as in A335711.
%Y Cf. A268371, A335711, A353067.
%K nonn
%O 1,2
%A _Jean-Luc Manguin_, Jul 15 2020
%E More terms from _John Mason_, Nov 04 2022