a(0)=1, a(n)=2^n+n^2-2*a(n-1).

Terms

a(0) =1a(1) =6a(2) =5a(3) =22a(4) =13a(5) =74a(6) =29a(7) =262a(8) =69a(9) =986a(10) =197a(11) =3846a(12) =669a(13) =15242a(14) =2509a(15) =60774a(16) =9813a(17) =242842a(18) =38965a(19) =971046a(20) =155501a(21) =3883786a(22) =621565a(23) =15534662a(24) =2485733a(25) =62138074a(26) =9942309a(27) =248551622a(28) =39768509a(29) =994205706