a(n) = n^6 - 11n^4 + 36n^2 - 36.

Terms

a(0) =-36a(1) =-10a(2) =-4a(3) =126a(4) =1820a(5) =9614a(6) =33660a(7) =92966a(8) =219356a(9) =462150a(10) =893564a(11) =1614830a(12) =2763036a(13) =4518686a(14) =7113980a(15) =10841814a(16) =16065500a(17) =23229206a(18) =32869116a(19) =45625310a(20) =62254364a(21) =83642670a(22) =110820476a(23) =144976646a(24) =187474140a(25) =239866214a(26) =303913340