Number of (n+3) X 4 0..2 matrices with each 4 X 4 subblock idempotent.

Terms

a(0) =2052a(1) =1623a(2) =2471a(3) =3506a(4) =4257a(5) =5737a(6) =8117a(7) =12306a(8) =18187a(9) =26561a(10) =38040a(11) =55162a(12) =80519a(13) =118413a(14) =173641a(15) =254339a(16) =371847a(17) =544345a(18) =797402a(19) =1169025a(20) =1713358a(21) =2510861a(22) =3678903a(23) =5391040a(24) =7900541a(25) =11579142a(26) =16970092a(27) =24870656a(28) =36448737a(29) =53417530