Number of blobs with vertical symmetry.

Terms

a(0) =1a(1) =1a(2) =4a(3) =15a(4) =62a(5) =262a(6) =1148a(7) =5123a(8) =23316a(9) =107570a(10) =502664a(11) =2372786a(12) =11302858a(13) =54256236a(14) =262226900a(15) =1274944859a(16) =6231845040a(17) =30605344282a(18) =150948390672a(19) =747356368322