Number of maximal 2-independent sets in the 3-dimensional (2, 2, n) grid graph.

Terms

a(0) =0a(1) =4a(2) =4a(3) =20a(4) =32a(5) =80a(6) =180a(7) =408a(8) =940a(9) =2072a(10) =4824a(11) =10792a(12) =24660a(13) =55748a(14) =126760a(15) =287584a(16) =652280a(17) =1481184a(18) =3359900a(19) =7627296a(20) =17305472a(21) =39277688a(22) =89131928a(23) =202276640a(24) =459045772a(25) =1041743020a(26) =2364140452a(27) =5365103100a(28) =12175556108a(29) =27630957644