Number of fixed-point free involutions in a fixed Sylow 2-subgroup of the symmetric group of degree 4n.
A332869
Number of fixed-point free involutions in a fixed Sylow 2-subgroup of the symmetric group of degree 4n.
Terms
- a(0) =1a(1) =3a(2) =17a(3) =51a(4) =417a(5) =1251a(6) =7089a(7) =21267a(8) =206657a(9) =619971a(10) =3513169a(11) =10539507a(12) =86175969a(13) =258527907a(14) =1464991473a(15) =4394974419a(16) =44854599297a(17) =134563797891a(18) =762528188049
External references
- oeis: A332869