Number of (n+6)X(n+6) 0..1 matrices with each 7X7 subblock idempotent.

Terms

a(0) =2185738a(1) =26918a(2) =21966a(3) =26528a(4) =31062a(5) =34588a(6) =37202a(7) =39188a(8) =51306a(9) =73564a(10) =103876a(11) =140148a(12) =180814a(13) =224838a(14) =271582a(15) =333314a(16) =421494a(17) =545192a(18) =711240a(19) =924840a(20) =1190134a(21) =1510622a(22) =1904402