The number of free kissing polyominoes with n cells.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =1a(7) =5a(8) =35a(9) =179a(10) =909a(11) =4287a(12) =19723a(13) =88240a(14) =388260a(15) =1683998a(16) =7227374a(17) =30750236