a(0)=0; thereafter a(n) = A238824(n-1)+A238825(n).

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =5a(5) =12a(6) =28a(7) =70a(8) =169a(9) =420a(10) =1030a(11) =2546a(12) =6266a(13) =15452a(14) =38056a(15) =93774a(16) =230993a(17) =569084a(18) =1401913a(19) =3453690a(20) =8508214a(21) =20960336a(22) =51636447a(23) =127208350a(24) =313382262a(25) =772028708a(26) =1901920456a(27) =4685449914a(28) =11542774524a(29) =28436041324