Number of arrangements of 9 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero.

A188255

Number of arrangements of 9 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero.

Terms

    a(0) =140a(1) =16272a(2) =355396a(3) =2880240a(4) =14715004a(5) =55994544a(6) =168083116a(7) =445304272a(8) =1033172284a(9) =2215496776a(10) =4323822892

External references