Number of even permutations p of {1,...,n} such that p(i) is not i or i+1.
A293042
Number of even permutations p of {1,...,n} such that p(i) is not i or i+1.
Terms
- a(0) =1a(1) =0a(2) =0a(3) =1a(4) =1a(5) =9a(6) =47a(7) =339a(8) =2705a(9) =24402a(10) =244294a(11) =2689669a(12) =32297985a(13) =420096147a(14) =5883813373a(15) =88287031271
External references
- oeis: A293042