Number of n X n 1..4 arrays with no element with value z exactly a city block distance of z from another element with value z.

A210780

Number of n X n 1..4 arrays with no element with value z exactly a city block distance of z from another element with value z.

Terms

    a(0) =4a(1) =176a(2) =21379a(3) =1115472a(4) =98861559a(5) =51104966068

External references