Number of permutations of 9..n+8 with no element greater than or equal to the sum of its neighbors.
A180897
Number of permutations of 9..n+8 with no element greater than or equal to the sum of its neighbors.
Terms
- a(0) =1a(1) =0a(2) =2a(3) =6a(4) =30a(5) =180a(6) =1260a(7) =10080a(8) =90720a(9) =907200a(10) =9797760a(11) =114287040a(12) =1416703680a(13) =18712086480a(14) =260499022680
External references
- oeis: A180897