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 two or three distinct values for every i<=n and j<=n.

A211461

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 two or three distinct values for every i<=n and j<=n.

Terms

    a(0) =24a(1) =56a(2) =128a(3) =254a(4) =516a(5) =982a(6) =1904a(7) =3578a(8) =6812a(9) =12786a(10) =24224a(11) =45658a(12) =86660a(13) =164422a(14) =313660a(15) =599546a(16) =1150980a(17) =2216138a(18) =4281996a(19) =8299742a(20) =16133004a(21) =31452126a(22) =61458520a(23) =120403946a(24) =236321944a(25) =464854866a(26) =915752544a(27) =1807260018a(28) =3570943416

External references