Number of (n+6)X7 0..2 matrices with each 7X7 subblock idempotent.

Terms

a(0) =145121216a(1) =10906923a(2) =6162817a(3) =4750292a(4) =4617228a(5) =4971859a(6) =5047936a(7) =5029695a(8) =5708639a(9) =7589727a(10) =11387955a(11) =17128394a(12) =24395022a(13) =33632312a(14) =44378240a(15) =56580772a(16) =72151138a(17) =94546333a(18) =128344682a(19) =179174727a(20) =253082925