Number of -3..3 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 one, two or three distinct values for every i<=n and j<=n.

A211501

Number of -3..3 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 one, two or three distinct values for every i<=n and j<=n.

Terms

    a(0) =49a(1) =143a(2) =357a(3) =879a(4) =2053a(5) =4805a(6) =10971a(7) =25233a(8) =57391a(9) =131643a(10) =300783a(11) =692847a(12) =1595765a(13) =3701759a(14) =8601369a(15) =20105533a(16) =47103881a(17) =110883033a(18) =261621763a(19) =619556193a(20) =1470188991a(21) =3498411151a(22) =8338717447a(23) =19916838255a(24) =47634215409a(25) =114096061487

External references