Number of (n+2) X 3 binary matrices with every 3 X 3 block having exactly four 1's.
A181255
Number of (n+2) X 3 binary matrices with every 3 X 3 block having exactly four 1's.
Terms
- a(0) =126a(1) =336a(2) =906a(3) =2484a(4) =7218a(5) =21024a(6) =61398a(7) =182520a(8) =542754a(9) =1614492a(10) =4829706a(11) =14448456a(12) =43225326a(13) =129555936a(14) =388309626a(15) =1163860164a(16) =3490511778a(17) =10468335024a(18) =31395421638a(19) =94176681480a(20) =282501311634a(21) =847417788972
External references
- oeis: A181255