Number of nX2 integer arrays with each element equal to the number of horizontal, vertical and antidiagonal neighbors exactly one smaller than itself.

A266019

Number of nX2 integer arrays with each element equal to the number of horizontal, vertical and antidiagonal neighbors exactly one smaller than itself.

Terms

    a(0) =3a(1) =7a(2) =14a(3) =42a(4) =99a(5) =259a(6) =719a(7) =1784a(8) =4792a(9) =12479a(10) =32263a(11) =86025a(12) =222663a(13) =585072a(14) =1535472a(15) =4002444a(16) =10527738a(17) =27516774a(18) =72060109a(19) =188952481a(20) =494214824a(21) =1295507675a(22) =3392305134a(23) =8882420053a(24) =23272852966a(25) =60933892273a(26) =159611564865a(27) =418043981246

External references