Possible traces of n-step walks on 1-D lattice, ignoring translations.

Terms

a(0) =1a(1) =2a(2) =4a(3) =7a(4) =14a(5) =23a(6) =45a(7) =72a(8) =137a(9) =217a(10) =402a(11) =635a(12) =1149a(13) =1816a(14) =3221a(15) =5101a(16) =8898a(17) =14127a(18) =24305a(19) =38688a(20) =65809a(21) =105009a(22) =176962a(23) =282995a(24) =473269a(25) =758312a(26) =1260253a(27) =2022661a(28) =3344354a(29) =5375207