Number of hexagonal polyominoes (or hexagonal polyforms, or planar polyhexes) with n cells.

A000228

Number of hexagonal polyominoes (or hexagonal polyforms, or planar polyhexes) with n cells.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =7a(4) =22a(5) =82a(6) =333a(7) =1448a(8) =6572a(9) =30490a(10) =143552a(11) =683101a(12) =3274826a(13) =15796897a(14) =76581875a(15) =372868101a(16) =1822236628a(17) =8934910362a(18) =43939164263a(19) =216651036012

External references