Number of nX4 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X5 binary array having a sum of one, with rows and columns of the latter in lexicographically nondecreasing order.
A227383
Number of nX4 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X5 binary array having a sum of one, with rows and columns of the latter in lexicographically nondecreasing order.
Terms
- a(0) =5a(1) =30a(2) =185a(3) =1104a(4) =6160a(5) =31073a(6) =141192a(7) =581706a(8) =2192737a(9) =7631150a(10) =24723499a(11) =75114814a(12) =215382006a(13) =586096131a(14) =1520882101a(15) =3779307010a(16) =9026380556a(17) =20787492011a(18) =46293089506a(19) =99943655427a(20) =209652253128a(21) =428180495383
External references
- oeis: A227383