Number of (n+5)X9 0..1 matrices with each 6X6 subblock idempotent.

Terms

a(0) =18868a(1) =6411a(2) =6659a(3) =7394a(4) =8143a(5) =8714a(6) =9164a(7) =10807a(8) =13624a(9) =17332a(10) =21731a(11) =26592a(12) =31785a(13) =38491a(14) =47899a(15) =60907a(16) =78205a(17) =100219a(18) =127312a(19) =161005a(20) =203975a(21) =259809a(22) =332836a(23) =427756a(24) =549639a(25) =705073a(26) =903350a(27) =1157341a(28) =1484238a(29) =1905898