Number of (n+1) X 6 0..1 matrices with each 2 X 2 subblock idempotent.

Terms

a(0) =80a(1) =137a(2) =193a(3) =294a(4) =428a(5) =635a(6) =943a(7) =1420a(8) =2162a(9) =3333a(10) =5193a(11) =8166a(12) =12936a(13) =20611a(14) =32983a(15) =52952a(16) =85210a(17) =137349a(18) =221653a(19) =357998a(20) =578544a(21) =935327a(22) =1512543a(23) =2446424a(24) =3957398a(25) =6402125a(26) =10357693a(27) =16757850a(28) =27113432a(29) =43869023