Ceiling(n*exp(-csc(n))).

Terms

a(0) =1a(1) =1a(2) =1a(3) =15a(4) =15a(5) =216a(6) =2a(7) =3a(8) =1a(9) =63a(10) =30a(11) =78a(12) =2a(13) =6a(14) =4a(15) =516a(16) =49a(17) =69a(18) =1a(19) =7a(20) =7a(22) =75a(23) =73a(24) =47787a(25) =8a(26) =10a(27) =1a(28) =131a(29) =83a(30) =369