1/3 of the number of permutations of 2 indistinguishable copies of 1..n with exactly 3 local maxima.

A152495

1/3 of the number of permutations of 2 indistinguishable copies of 1..n with exactly 3 local maxima.

Terms

    a(0) =0a(1) =0a(2) =8a(3) =483a(4) =16205a(5) =430078a(6) =10210206a(7) =228926441a(8) =4979392831a(9) =106552681812

External references