Number of alternating permutations of the multiset {1,1,2,2,...,n,n}.
A275801
Number of alternating permutations of the multiset {1,1,2,2,...,n,n}.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =4a(4) =53a(5) =936a(6) =25325a(7) =933980a(8) =45504649a(9) =2824517520a(10) =217690037497
External references
- oeis: A275801