Number of asymmetrical dissections of n-gon.

Terms

a(0) =2a(1) =5a(2) =21a(3) =61a(4) =214a(5) =669a(6) =2240a(7) =7330a(8) =24695a(9) =83257a(10) =284928a(11) =981079a(12) =3410990a(13) =11937328a(14) =42075242a(15) =149171958a(16) =531866972a(17) =1905842605a(18) =6861162880a(19) =24805692978a(20) =90035940227a(21) =327987890608