Number of configurations in the Classic Lights Out puzzle with n lights on.

Terms

a(0) =1a(1) =5a(2) =72a(3) =576a(4) =3166a(5) =13326a(6) =44256a(7) =119944a(8) =270531a(9) =511319a(10) =816752a(11) =1113504a(12) =1300852a(13) =1300852a(14) =1113504a(15) =816752a(16) =511319a(17) =270531a(18) =119944a(19) =44256a(20) =13326a(21) =3166a(22) =576a(23) =72a(24) =5a(25) =1