A089454 Number of n-celled polyominoes with exactly 2 holes.
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 41, 346, 2384, 14560, 81863, 433172, 2192752, 10726252, 51094203, 238259280, 1092053068, 4934652298, 22034767837, 97407519119, 426916828181
Offset: 1
Links
- Tomás Oliveira e Silva, Animal enumerations on the {4,4} Euclidean tiling