Let f(n) = A004001(n)^2 - A005185(n)^2. Then a(n) = f(abs(f(n-1))) + f(abs(n - f(n-1))).

Terms

a(0) =0a(1) =-3a(2) =-14a(3) =-18a(4) =-7a(5) =-9a(6) =-47a(7) =-51a(8) =0a(9) =-15a(10) =-15a(11) =-48a(12) =-17a(13) =-36a(14) =57a(15) =-151a(16) =0a(17) =-63a(18) =0a(19) =-11a(20) =0a(21) =25a(22) =26a(23) =368a(24) =29a(25) =-5a(26) =-96a(27) =-33a(28) =0a(29) =-144