Number of squarefree permutations of 1,...,n that are fixed under reverse-complement, up to symmetry.
A238942
Number of squarefree permutations of 1,...,n that are fixed under reverse-complement, up to symmetry.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =0a(4) =3a(5) =0a(6) =7a(7) =0a(8) =32a(9) =0a(10) =113a(11) =0a(12) =606a(13) =0a(14) =2340a(15) =0a(16) =19941a(17) =0a(18) =122868a(19) =0a(20) =1086205a(21) =0a(22) =6508459a(23) =0a(24) =85816852a(25) =0
External references
- oeis: A238942