Number of asymmetric n-celled polyominoes with 1 hole.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =5a(8) =31a(9) =185a(10) =947a(11) =4564a(12) =21004a(13) =93833a(14) =410295a(15) =1765378a(16) =7504024a(17) =31591157a(18) =131982937a(19) =547971412a(20) =2263443059a(21) =9309302775a(22) =38149945673a(23) =155858903955a(24) =635066943350