p-INVERT of (1,1,2,2,3,3,...) (A008619), where p(S) = 1 - S - S^2.

Terms

a(0) =1a(1) =3a(2) =9a(3) =26a(4) =74a(5) =211a(6) =600a(7) =1708a(8) =4860a(9) =13832a(10) =39364a(11) =112029a(12) =318827a(13) =907366a(14) =2582312a(15) =7349121a(16) =20915193a(17) =59523497a(18) =169400608a(19) =482104856a(20) =1372044007a(21) =3904762096a(22) =11112739032a(23) =31626246588a(24) =90006565434a(25) =256153755080a(26) =728999555983