Number of n X 1 0..4 arrays with each element equal to the number its horizontal and vertical neighbors less than itself.

A196423

Number of n X 1 0..4 arrays with each element equal to the number its horizontal and vertical neighbors less than itself.

Terms

    a(0) =1a(1) =3a(2) =5a(3) =11a(4) =26a(5) =55a(6) =119a(7) =263a(8) =573a(9) =1248a(10) =2729a(11) =5959a(12) =13005a(13) =28399a(14) =62010a(15) =135383a(16) =295595a(17) =645407a(18) =1409161a(19) =3076736a(20) =6717713a(21) =14667339a(22) =32024421a(23) =69921635a(24) =152665786a(25) =333328023a(26) =727783135a(27) =1589030151a(28) =3469463141a(29) =7575170720

External references