Number of one-sided polyarcs with n cells.

Terms

a(0) =2a(1) =11a(2) =36a(3) =169a(4) =702a(5) =3411a(6) =16372a(7) =81798a(8) =412696a(9) =2112362a(10) =10907492a(11) =56782983a(12) =297599786a(13) =1568750187