a(2n) = Lucas(2n+3)^2, a(2n+1) = Lucas(2n+1)^2.

Terms

a(0) =16a(1) =1a(2) =121a(3) =16a(4) =841a(5) =121a(6) =5776a(7) =841a(8) =39601a(9) =5776a(10) =271441a(11) =39601a(12) =1860496a(13) =271441a(14) =12752041a(15) =1860496a(16) =87403801a(17) =12752041a(18) =599074576a(19) =87403801a(20) =4106118241a(21) =599074576a(22) =28143753121a(23) =4106118241a(24) =192900153616a(25) =28143753121