A167247 Number of ways to partition an n X 4 grid into 2 connected equal-area regions.

1, 4, 19, 70, 245, 856, 2967, 10164, 34463, 115904, 387379, 1288574, 4270853, 14116936, 46567963, 153385198

Offset: 1

Author

R. H. Hardin, Oct 31 2009

Keywords

• nonn
• more

Examples

			All solutions for n=3
...1.1.1.1...1.1.1.1...1.1.1.1...1.1.1.1...1.1.1.1...1.1.1.1...1.1.1.1
...1.1.2.2...1.2.1.2...1.2.2.1...1.2.2.2...2.1.1.2...2.1.2.1...2.2.1.1
...2.2.2.2...2.2.2.2...2.2.2.2...1.2.2.2...2.2.2.2...2.2.2.2...2.2.2.2
------
...1.1.1.1...1.1.1.2...1.1.1.2...1.1.1.2...1.1.1.2...1.1.2.2...1.1.2.2
...2.2.2.1...1.1.1.2...1.1.2.2...1.2.1.2...1.2.2.2...1.1.1.2...1.1.2.2
...2.2.2.1...2.2.2.2...1.2.2.2...1.2.2.2...1.1.2.2...1.2.2.2...1.1.2.2
------
...1.1.2.2...1.2.2.2...1.2.2.2...1.2.2.2...1.2.2.2
...1.2.2.2...1.1.1.2...1.1.2.2...1.2.1.2...1.2.2.2
...1.1.1.2...1.1.2.2...1.1.1.2...1.1.1.2...1.1.1.1
		

Links

• Manuel Kauers, Christoph Koutschan, and George Spahn, A348456(4) = 7157114189, arXiv:2209.01787 [math.CO], 2022.
• Manuel Kauers, Christoph Koutschan, and George Spahn, How Does the Gerrymander Sequence Continue?, J. Int. Seq., Vol. 25 (2022), Article 22.9.7.

Crossrefs

Cf. A167242, A348456.