Number of permutations of {1..n} with the sum of squared adjacent differences < n*(n+1)/2.
A180071
Number of permutations of {1..n} with the sum of squared adjacent differences < n*(n+1)/2.
Terms
- a(0) =0a(1) =1a(2) =2a(3) =6a(4) =12a(5) =24a(6) =98a(7) =344a(8) =1236a(9) =5332a(10) =23772a(11) =110962a(12) =547714a(13) =2840028a(14) =15439466a(15) =87299850a(16) =512569668a(17) =3111575102a(18) =19577613014a(19) =127331688104a(20) =852129210498
External references
- oeis: A180071