Call two meanders from A005316 equivalent if they differ by a reflection in the Y axis (if n even) or by reflections in the X or Y axes (if n odd). Sequence gives number of inequivalent meanders with n crossings.
A077055
Call two meanders from A005316 equivalent if they differ by a reflection in the Y axis (if n even) or by reflections in the X or Y axes (if n odd). Sequence gives number of inequivalent meanders with n crossings.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =8a(6) =13a(7) =42a(8) =72a(9) =273a(10) =475a(11) =1970a(12) =3506a(13) =15368a(14) =27888a(15) =126510a(16) =233809a(17) =1086546a(18) =2039564a(19) =9652364a(20) =18360296a(21) =88172609a(22) =169610371a(23) =824506191a(24) =1601297937a(25) =7865294687a(26) =15401847339a(27) =76331857094a(28) =150547538649a(29) =751981532942
External references
- oeis: A077055