Triangle by rows T(n,k), showing the number of meanders with length 5(n+1) and containing 5(k+1) L's and 5(n-k) R's, where L's and R's denote arcs of equal length and a central angle of 72 degrees which are positively or negatively oriented.
A197654
Triangle by rows T(n,k), showing the number of meanders with length 5(n+1) and containing 5(k+1) L's and 5(n-k) R's, where L's and R's denote arcs of equal length and a central angle of 72 degrees which are positively or negatively oriented.
Terms
- a(0) =1a(1) =5a(2) =1a(3) =31a(4) =62a(5) =1a(6) =121a(7) =1215a(8) =363a(9) =1a(10) =341a(11) =13504a(12) =20256a(13) =1364a(14) =1a(15) =781a(16) =96875a(17) =500000a(18) =193750a(19) =3905a(20) =1a(21) =1555a(22) =501066a(23) =7321875a(24) =9762500a(25) =1252665a(26) =9330a(27) =1a(28) =2801a(29) =2033647
External references
- oeis: A197654