Number of (n+1)X(3+1) 0..1 arrays with 2X2 subblock sums lexicographically nondecreasing rowwise and nonincreasing columnwise.
A235408
Number of (n+1)X(3+1) 0..1 arrays with 2X2 subblock sums lexicographically nondecreasing rowwise and nonincreasing columnwise.
Terms
- a(0) =121a(1) =704a(2) =4256a(3) =20398a(4) =98575a(5) =397340a(6) =1623115a(7) =5744912a(8) =20612708a(9) =65877470a(10) =213190201a(11) =627225413a(12) =1867007833a(13) =5131067959a(14) =14261504547a(15) =37041121138a(16) =97280493869a(17) =241057367009a(18) =603912355679
External references
- oeis: A235408