Number of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly 2 local maxima.

A159716

Number of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly 2 local maxima.

Terms

    a(0) =2a(1) =66a(2) =1168a(3) =16220a(4) =202416a(5) =2395540a(6) =27517568a(7) =310123764a(8) =3447919120a(9) =37934904788a(10) =413863668480

External references