Number of pairs of orthogonal (diagonal, antidiagonal) X-rays for all permutations of [n].
A290280
Number of pairs of orthogonal (diagonal, antidiagonal) X-rays for all permutations of [n].
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =23a(5) =115a(6) =674a(7) =4718a(8) =37371a(9) =335435a(10) =3340116
External references
- oeis: A290280