Number of fixed convex polyominoes with n cells.

Terms

a(0) =1a(1) =2a(2) =6a(3) =19a(4) =59a(5) =176a(6) =502a(7) =1374a(8) =3630a(9) =9312a(10) =23320a(11) =57279a(12) =138536a(13) =331032a(14) =783630a(15) =1841867a(16) =4306172a(17) =10028276a(18) =23288394a(19) =53974959a(20) =124925967a(21) =288878550a(22) =667602492a(23) =1542254655a(24) =3562000916a(25) =8225719574a(26) =18994263354a(27) =43858728367a(28) =101270779744a(29) =233836327750