One half of the sum of the perimeters of the free polyominoes with n cells.
A380575
One half of the sum of the perimeters of the free polyominoes with n cells.
Terms
- a(0) =2a(1) =3a(2) =8a(3) =24a(4) =71a(5) =236a(6) =835a(7) =3182a(8) =12302a(9) =48834a(10) =195035a(11) =785280a(12) =3167322a(13) =12808531a(14) =51834644a(15) =209965222a(16) =850817523a(17) =3449091525
External references
- oeis: A380575