Number of nX1 0..4 arrays with each element equal to the number its horizontal and vertical neighbors less than or equal to itself.

A196537

Number of nX1 0..4 arrays with each element equal to the number its horizontal and vertical neighbors less than or equal to itself.

Terms

    a(0) =1a(1) =3a(2) =2a(3) =7a(4) =19a(5) =35a(6) =77a(7) =176a(8) =377a(9) =819a(10) =1801a(11) =3927a(12) =8562a(13) =18711a(14) =40855a(15) =89179a(16) =194729a(17) =425184a(18) =928305a(19) =2026855a(20) =4425441a(21) =9662395a(22) =21096706a(23) =46062279a(24) =100571611a(25) =219586403a(26) =479441557a(27) =1046805072a(28) =2285577449a(29) =4990293595

External references