a(n) = A055498(n) - A055500(n).

Terms

a(0) =-1a(1) =0a(2) =0a(3) =0a(4) =0a(5) =4a(6) =6a(7) =12a(8) =24a(9) =42a(10) =68a(11) =122a(12) =208a(13) =336a(14) =552a(15) =904a(16) =1464a(17) =2378a(18) =3848a(19) =6232a(20) =10090a(21) =16338a(22) =26446a(23) =42802a(24) =69252a(25) =112072a(26) =181332a(27) =293412a(28) =474762a(29) =768190