Number of permutations of 3 indistinguishable copies of 1..n arranged in a circle with exactly 1 local maximum.
A159721
Number of permutations of 3 indistinguishable copies of 1..n arranged in a circle with exactly 1 local maximum.
Terms
- a(0) =6a(1) =36a(2) =192a(3) =960a(4) =4608a(5) =21504a(6) =98304a(7) =442368a(8) =1966080a(9) =8650752a(10) =37748736a(11) =163577856a(12) =704643072a(13) =3019898880a(14) =12884901888a(15) =54760833024a(16) =231928233984a(17) =979252543488
External references
- oeis: A159721