Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with x(i)+x(j), x(i+1)+x(j+1), -(x(i)+x(j+1)), and -(x(i+1)+x(j)) having three or four distinct values for every i<=n and j<=n.

A211463

Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with x(i)+x(j), x(i+1)+x(j+1), -(x(i)+x(j+1)), and -(x(i+1)+x(j)) having three or four distinct values for every i<=n and j<=n.

Terms

    a(0) =20a(1) =80a(2) =304a(3) =1144a(4) =4232a(5) =15536a(6) =56616a(7) =205400a(8) =742608a(9) =2678752a(10) =9648024a(11) =34716712a(12) =124861664a(13) =449008336a(14) =1614830152a(15) =5809328408a(16) =20907961552a(17) =75287770240a(18) =271263934328a(19) =977981837448

External references