a(0) = 1, a(n) = Sum_{k=1..n} a(n-k)*ceiling(sin(k)).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =7a(5) =13a(6) =24a(7) =45a(8) =84a(9) =157a(10) =293a(11) =547a(12) =1021a(13) =1906a(14) =3558a(15) =6642a(16) =12399a(17) =23146a(18) =43208a(19) =80659a(20) =150571a(21) =281080a(22) =524709a(23) =979506a(24) =1828503a(25) =3413376a(26) =6371955a(27) =11894912a(28) =22204949a(29) =41451316