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

Terms

a(0) =2052a(1) =1920a(2) =3092a(3) =3924a(4) =4498a(5) =7090a(6) =11268a(7) =16568a(8) =22726a(9) =32326a(10) =47310a(11) =69124a(12) =98934a(13) =141122a(14) =202398a(15) =291280a(16) =417790a(17) =597382a(18) =853688a(19) =1220732a(20) =1744804a(21) =2491066a(22) =3553342a(23) =5066576a(24) =7221562a(25) =10287590a(26) =14646626a(27) =20842212a(28) =29645776