Number of signed permutations of length n avoiding (-2, 1) and (2, -1).
A193763
Number of signed permutations of length n avoiding (-2, 1) and (2, -1).
Terms
- a(0) =1a(1) =2a(2) =6a(3) =22a(4) =94a(5) =462a(6) =2606a(7) =16862a(8) =124782a(9) =1048990a(10) =9921550a(11) =104447550a(12) =1211190638a(13) =15329157278a(14) =210093682254
External references
- oeis: A193763