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.
A322069
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) =3a(6) =1a(7) =7a(8) =13a(9) =83a(10) =84a(11) =540a(12) =480a(13) =5488a(14) =48922
External references
- oeis: A322069