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

Terms

a(0) =1a(1) =3a(2) =9a(3) =26a(4) =74a(5) =210a(6) =596a(7) =1692a(8) =4804a(9) =13640a(10) =38728a(11) =109960a(12) =312208a(13) =886448a(14) =2516880a(15) =7146144a(16) =20289952a(17) =57608992a(18) =163568448a(19) =464417728a(20) =1318615104a(21) =3743926400a(22) =10630080640a(23) =30181847168a(24) =85694918912a(25) =243312448256a(26) =690833811712