Number of permutations of 1..n with no four elements in correct or reverse order.
A095817
Number of permutations of 1..n with no four elements in correct or reverse order.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =22a(5) =114a(6) =692a(7) =4884a(8) =39318a(9) =355490a(10) =3567292a(11) =39345804a(12) =473148014a(13) =6161310442a(14) =86376341412
External references
- oeis: A095817