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

A211688

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

Terms

    a(0) =69a(1) =173a(2) =375a(3) =765a(4) =1545a(5) =3029a(6) =5973a(7) =11621a(8) =22759a(9) =44341a(10) =86833a(11) =169841a(12) =333421a(13) =654917a(14) =1289687a(15) =2542733a(16) =5021945a(17) =9931349a(18) =19663237a(19) =38977973a(20) =77326087a(21) =153558325a(22) =305104801a(23) =606719185a(24) =1206917981a(25) =2402499477a(26) =4783531511

External references