Number of horizontal, vertical and diagonal neighbor colorings of the even squares of an n X 2 array with new integer colors introduced in row major order.

A215953

Number of horizontal, vertical and diagonal neighbor colorings of the even squares of an n X 2 array with new integer colors introduced in row major order.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =12a(5) =34a(6) =136a(7) =500a(8) =2440a(9) =10900a(10) =61912a(11) =322768a(12) =2075312a(13) =12297768a(14) =87852160a(15) =580849872a(16) =4548247264a(17) =33093252880a(18) =281121815712

External references