Number of permutations f of {1,...,n} with f(1) < f(n) such that Sum_{k=1..n-1} 1/(f(k)+f(k+1)) = 1.
A322070
Number of permutations f of {1,...,n} with f(1) < f(n) such that Sum_{k=1..n-1} 1/(f(k)+f(k+1)) = 1.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =1a(7) =8a(8) =22a(9) =98a(10) =844a(11) =3831a(12) =20922a(13) =88902a(14) =358253
External references
- oeis: A322070