Jacobsthal reverse-pair sequence.

Terms

a(0) =0a(1) =1a(2) =1a(3) =5a(4) =3a(5) =21a(6) =11a(7) =85a(8) =43a(9) =341a(10) =171a(11) =1365a(12) =683a(13) =5461a(14) =2731a(15) =21845a(16) =10923a(17) =87381a(18) =43691a(19) =349525a(20) =174763a(21) =1398101a(22) =699051a(23) =5592405a(24) =2796203a(25) =22369621a(26) =11184811a(27) =89478485a(28) =44739243a(29) =357913941