Number of (n+1) X (n+1) -8..8 symmetric matrices with every 2 X 2 subblock having sum zero and one or two distinct values.

A211466

Number of (n+1) X (n+1) -8..8 symmetric matrices with every 2 X 2 subblock having sum zero and one or two distinct values.

Terms

    a(0) =25a(1) =33a(2) =45a(3) =65a(4) =97a(5) =149a(6) =233a(7) =369a(8) =589a(9) =945a(10) =1521a(11) =2453a(12) =3961a(13) =6401a(14) =10349a(15) =16737a(16) =27073a(17) =43797a(18) =70857a(19) =114641a(20) =185485a(21) =300113a(22) =485585a(23) =785685a(24) =1271257a(25) =2056929a(26) =3328173a(27) =5385089a(28) =8713249a(29) =14098325

External references