Number of indefinitely growing n-step self-avoiding walks on Manhattan lattice.

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =13a(5) =24a(6) =43a(7) =77a(8) =139a(9) =249a(10) =443a(11) =786a(12) =1400a(13) =2486a(14) =4395a(15) =7758a(16) =13732a(17) =24251a(18) =42710a(19) =75154a(20) =132487a(21) =233173a(22) =409617a(23) =719157a(24) =1264303a(25) =2219916a(26) =3892603a(27) =6822808a(28) =11970965a(29) =20983162