Number of n-celled diagonally symmetric polyominoes without holes.

Terms

a(0) =0a(1) =0a(2) =1a(3) =0a(4) =2a(5) =2a(6) =6a(7) =5a(8) =21a(9) =18a(10) =70a(11) =61a(12) =239a(13) =206a(14) =828a(15) =711a(16) =2903a(17) =2485a(18) =10314a(19) =8791a(20) =37031a(21) =31451a(22) =134147a(23) =113566a(24) =489672a(25) =413419a(26) =1799084a(27) =1515282a(28) =6647009a(29) =5586834