a(n) is the number of signed permutations W of V = (1, 2, ..., n) such that the dot product V*W = 0.

A358629

a(n) is the number of signed permutations W of V = (1, 2, ..., n) such that the dot product V*W = 0.

Terms

    a(0) =0a(1) =2a(2) =0a(3) =16a(4) =48a(5) =558a(6) =4444a(7) =62246a(8) =692598a(9) =11722730a(10) =196824592a(11) =3896202680a(12) =86626174698

External references