p-INVERT of the positive integers (A000027), where p(S) = 1 - S - S^2.

Terms

a(0) =1a(1) =4a(2) =14a(3) =47a(4) =156a(5) =517a(6) =1714a(7) =5684a(8) =18851a(9) =62520a(10) =207349a(11) =687676a(12) =2280686a(13) =7563923a(14) =25085844a(15) =83197513a(16) =275925586a(17) =915110636a(18) =3034975799a(19) =10065534960a(20) =33382471801a(21) =110713382644a(22) =367182309614