1/4 the number of permutations of 3 indistinguishable copies of 1..n with exactly 3 local maxima.
A152500
1/4 the number of permutations of 3 indistinguishable copies of 1..n with exactly 3 local maxima.
Terms
- a(0) =0a(1) =1a(2) =231a(3) =21490a(4) =1476084a(5) =90050080a(6) =5228286336a(7) =297239712256
External references
- oeis: A152500