1-sequence of reduction of (2n) by x^2 -> x+1.

Terms

a(0) =0a(1) =4a(2) =10a(3) =26a(4) =56a(5) =116a(6) =228a(7) =436a(8) =814a(9) =1494a(10) =2704a(11) =4840a(12) =8584a(13) =15108a(14) =26418a(15) =45938a(16) =79496a(17) =136988a(18) =235180a(19) =402420a(20) =686550a(21) =1168174a(22) =1982880a(23) =3358416a(24) =5676816a(25) =9578116a(26) =16133338a(27) =27132746a(28) =45565784a(29) =76419524