a(n) = Pell(n)*A001227(n) for n >= 1, where A001227(n) is the number of odd divisors of n.

Terms

a(0) =1a(1) =2a(2) =10a(3) =12a(4) =58a(5) =140a(6) =338a(7) =408a(8) =2955a(9) =4756a(10) =11482a(11) =27720a(12) =66922a(13) =161564a(14) =780100a(15) =470832a(16) =2273378a(17) =8232630a(18) =13250218a(19) =31988856a(20) =154455860a(21) =186444716a(22) =450117362a(23) =1086679440a(24) =3935214363a(25) =6333631924a(26) =30581480180a(27) =36915112104a(28) =89120964298a(29) =430314081400