Number of (n+1) X 8 0..2 matrices with each 2 X 2 subblock idempotent.

Terms

a(0) =308a(1) =470a(2) =617a(3) =864a(4) =1166a(5) =1608a(6) =2230a(7) =3157a(8) =4554a(9) =6711a(10) =10083a(11) =15415a(12) =23907a(13) =37504a(14) =59351a(15) =94538a(16) =151300a(17) =242962a(18) =391084a(19) =630551a(20) =1017808a(21) =1644185a(22) =2657457a(23) =4296729a(24) =6948881a(25) =11239898a(26) =18182645a(27) =29415972a(28) =47591594a(29) =77000076