Number of n step self-avoiding walks on 3 X infinity grid starting from (0,1).

Terms

a(0) =1a(1) =4a(2) =10a(3) =22a(4) =42a(5) =90a(6) =182a(7) =382a(8) =742a(9) =1486a(10) =2866a(11) =5646a(12) =10878a(13) =21198a(14) =40694a(15) =78758a(16) =151018a(17) =291046a(18) =557746a(19) =1072050a(20) =2053586a(21) =3941038a(22) =7547726a(23) =14471102a(24) =27711106a(25) =53099670a(26) =101675030a(27) =194762778a(28) =372916642a(29) =714195242