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 distinct values for every i<=n and j<=n.

A211459

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 distinct values for every i<=n and j<=n.

Terms

    a(0) =20a(1) =44a(2) =92a(3) =178a(4) =348a(5) =658a(6) =1260a(7) =2382a(8) =4548a(9) =8658a(10) =16604a(11) =31894a(12) =61596a(13) =119362a(14) =232212a(15) =453438a(16) =887916a(17) =1744602a(18) =3434636a(19) =6780910a(20) =13405764a(21) =26561986a(22) =52679004a(23) =104653254a(24) =208038684a(25) =414084306a(26) =824553428a(27) =1643457646a(28) =3276588012

External references