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

1,2

Links

Table of n, a(n) for n=1..16.

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.

Example

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

Crossrefs

Sequence in context: A291888 A217324 A129019 * A267192 A219972 A284224

Adjacent sequences: A167244 A167245 A167246 * A167248 A167249 A167250

Keyword

nonn,more

Author

R. H. Hardin, Oct 31 2009

Status

approved