Number of closed meanders with 2n crossings and 5 digons.

Terms

a(0) =16a(1) =40a(2) =168a(3) =280a(4) =544a(5) =1152a(6) =1560a(7) =2640a(8) =3504a(9) =5824a(10) =6552a(11) =12000a(12) =11456a(13) =19176a(14) =18648a(15) =31312a(16) =30640a(17) =50064a(18) =43736a(19) =71392a(20) =62304a(21) =104800a(22) =87672a(23) =141048a(24) =121968a(25) =191632a(26) =154200a(27) =255192a(28) =209536a(29) =327360