A336267 Number of free polyominoes of width 3 and height n.

1, 6, 24, 181, 941, 4662, 23691, 119271, 603760, 3050402, 15428576, 78004550, 394462578, 1994595585, 10086050889, 51001111356, 257894037378, 1304071170194, 6594196094078, 33344335235915, 168609627579175, 852594638783225, 4311246376730011

Offset

1,2

Comments

The sequence can be generated using a series of recursive formulas in a fashion similar to A353067. - John Mason, Nov 04 2022

Links

John Mason, Table of n, a(n) for n = 1..400

Example

a(2)=6, bounding box 2 X 3 as in A335711.

Crossrefs

Cf. A268371, A335711, A353067.

Sequence in context: A293488 A038033 A064049 * A018981 A052594 A372136

Adjacent sequences: A336264 A336265 A336266 * A336268 A336269 A336270

Keyword

nonn

Author

Jean-Luc Manguin, Jul 15 2020

Extensions

More terms from John Mason, Nov 04 2022

Status

approved