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

Terms

a(0) =115a(1) =191a(2) =257a(3) =381a(4) =542a(5) =793a(6) =1166a(7) =1746a(8) =2650a(9) =4080a(10) =6355a(11) =9996a(12) =15843a(13) =25257a(14) =40439a(15) =64951a(16) =104556a(17) =168579a(18) =272108a(19) =439556a(20) =710424a(21) =1148626a(22) =1857577a(23) =3004606a(24) =4860457a(25) =7863203a(26) =12721661a(27) =20582721a(28) =33302090a(29) =53882365