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

Terms

a(0) =2a(1) =7a(2) =22a(3) =68a(4) =208a(5) =632a(6) =1912a(7) =5768a(8) =17368a(9) =52232a(10) =156952a(11) =471368a(12) =1415128a(13) =4247432a(14) =12746392a(15) =38247368a(16) =114758488a(17) =344308232a(18) =1032990232a(19) =3099101768a(20) =9297567448a(21) =27893226632a(22) =83680728472a(23) =251044282568a(24) =753137042008