Number of asymmetric n-celled polyominoes without holes.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =5a(5) =20a(6) =84a(7) =311a(8) =1165a(9) =4276a(10) =15802a(11) =58280a(12) =216070a(13) =803116a(14) =2997360a(15) =11221443a(16) =42147842a(17) =158749808a(18) =599513836a(19) =2269390757a(20) =8609258335a(21) =32725209938a(22) =124621150623a(23) =475367241264