A167243 - OEIS

A167243

Number of ways to partition an n X 3 grid into 3 connected equal-area regions.

1, 3, 10, 23, 56, 132, 259, 546, 1095, 2043, 3908, 7379, 13208, 24194, 43819, 76790, 136489, 241311, 416152, 726073, 1261696, 2153026, 3706393, 6364842, 10775173, 18374181

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..26.

EXAMPLE

All solutions for n=4

...1.1.2...1.1.2...1.1.2...1.1.2...1.1.2...1.1.2...1.1.1...1.1.1...1.1.1

...1.2.2...1.2.2...1.1.2...1.1.2...1.3.2...3.1.2...1.2.2...1.2.2...1.2.2

...1.2.3...1.3.2...3.2.2...3.3.2...1.3.2...3.1.2...2.2.3...3.2.2...3.3.2

...3.3.3...3.3.3...3.3.3...3.3.2...3.3.2...3.3.2...3.3.3...3.3.3...3.3.2

------

...1.1.1...1.1.1...1.1.1...1.1.1...1.1.1...1.1.1...1.1.1...1.2.2...1.2.2

...1.2.3...2.2.1...2.2.1...2.2.1...2.1.3...2.1.3...2.3.1...1.2.2...1.2.2

...2.2.3...2.2.3...2.3.3...3.2.2...2.2.3...2.3.3...2.3.3...1.1.3...1.3.3

...2.3.3...3.3.3...2.3.3...3.3.3...2.3.3...2.2.3...2.2.3...3.3.3...1.3.3

------

...1.2.2...1.2.2...1.2.2...1.2.2...1.2.3

...1.2.3...1.1.2...1.1.2...1.3.2...1.2.3

...1.2.3...1.3.2...3.1.2...1.3.2...1.2.3

...1.3.3...3.3.3...3.3.3...1.3.3...1.2.3

CROSSREFS

Cf. A167242.

Sequence in context: A294503 A080204 A115982 * A316403 A185828 A134438

Adjacent sequences: A167240 A167241 A167242 * A167244 A167245 A167246

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 31 2009

STATUS

approved