1/10 of the number of permutations of 4 indistinguishable copies of 1..n with exactly 2 local maxima.

A152504

1/10 of the number of permutations of 4 indistinguishable copies of 1..n with exactly 2 local maxima.

Terms

    a(0) =0a(1) =3a(2) =140a(3) =5175a(4) =183000a(5) =6416875a(6) =224662500a(7) =7863609375a(8) =275228750000

External references