Number of -4..4 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 distinct values for every i<=n and j<=n.

A211687

Number of -4..4 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 distinct values for every i<=n and j<=n.

Terms

    a(0) =68a(1) =156a(2) =318a(3) =604a(4) =1144a(5) =2108a(6) =3924a(7) =7236a(8) =13486a(9) =25108a(10) =47168a(11) =88856a(12) =168588a(13) =321220a(14) =615390a(15) =1184204a(16) =2288040a(17) =4438780a(18) =8636484a(19) =16862164a(20) =32990542a(21) =64729172a(22) =127184496a(23) =250474872a(24) =493763644a(25) =975154132a(26) =1927138430a(27) =3814135532

External references