Number of chains in the poset of even-sized subsets of {1,2,...,n} ordered by inclusion.
A260464
Number of chains in the poset of even-sized subsets of {1,2,...,n} ordered by inclusion.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =7a(4) =27a(5) =91a(6) =483a(7) =2227a(8) =15627a(9) =92491a(10) =810963a(11) =5866147a(12) =61720827a(13) =527635291a(14) =6476783043a(15) =63886537267a(16) =896245131627
External references
- oeis: A260464