Sums of ménage numbers.

Terms

a(0) =1a(1) =0a(2) =0a(3) =1a(4) =3a(5) =16a(6) =96a(7) =675a(8) =5413a(9) =48800a(10) =488592a(11) =5379333a(12) =64595975a(13) =840192288a(14) =11767626752a(15) =176574062535