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

A211500

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

Terms

    a(0) =48a(1) =130a(2) =298a(3) =660a(4) =1384a(5) =2890a(6) =5850a(7) =11930a(8) =23806a(9) =48056a(10) =95422a(11) =191866a(12) =380806a(13) =765090a(14) =1521180a(15) =3058882a(16) =6098874a(17) =12284898a(18) =24573634a(19) =49602712a(20) =99555058a(21) =201409462a(22) =405573782a(23) =822380214a(24) =1661216936a(25) =3375887170a(26) =6839392998

External references