Order of alternating group A_n, or number of even permutations of n letters.

A001710

Order of alternating group A_n, or number of even permutations of n letters.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =3a(4) =12a(5) =60a(6) =360a(7) =2520a(8) =20160a(9) =181440a(10) =1814400a(11) =19958400a(12) =239500800a(13) =3113510400a(14) =43589145600a(15) =653837184000

External references