a(n) = +1476*a(n-6) +46656*a(n-12).

Terms

a(0) =0a(1) =1a(2) =2a(3) =2a(4) =40a(5) =228a(6) =228a(7) =1440a(8) =4248a(9) =4248a(10) =60336a(11) =336528a(12) =336528a(13) =2172096a(14) =6363360a(15) =6363360a(16) =90922176a(17) =507352896a(18) =507352896a(19) =3273198336a(20) =9590514048a(21) =9590514048a(22) =137016168192a(23) =764553924864a(24) =764553924864