Convolution of A000219 and A001477.

Terms

a(0) =0a(1) =1a(2) =3a(3) =8a(4) =19a(5) =43a(6) =91a(7) =187a(8) =369a(9) =711a(10) =1335a(11) =2459a(12) =4442a(13) =7904a(14) =13851a(15) =23965a(16) =40958a(17) =69248a(18) =115872a(19) =192097a(20) =315652a(21) =514485a(22) =832112a(23) =1336214a(24) =2131099a(25) =3377178a(26) =5319290a(27) =8330147a(28) =12973662a(29) =20100411