Third column of triangle A028364.

Terms

a(0) =5a(1) =9a(2) =23a(3) =66a(4) =202a(5) =645a(6) =2123a(7) =7150a(8) =24518a(9) =85306a(10) =300390a(11) =1068484a(12) =3833364a(13) =13855085a(14) =50401395a(15) =184392150a(16) =677998830a(17) =2504191470a(18) =9286661010a(19) =34564913820a(20) =129077071500a(21) =483474711330