Number of 2-element intersecting families of an n-element set; number of 2-way interactions when 2 subsets of power set on {1..n} are chosen at random.
A036239
Number of 2-element intersecting families of an n-element set; number of 2-way interactions when 2 subsets of power set on {1..n} are chosen at random.
Terms
- a(0) =0a(1) =2a(2) =15a(3) =80a(4) =375a(5) =1652a(6) =7035a(7) =29360a(8) =120975a(9) =494252a(10) =2007555a(11) =8120840a(12) =32753175a(13) =131818052a(14) =529680075a(15) =2125927520a(16) =8525298975a(17) =34165897052a(18) =136857560595a(19) =548011897400
External references
- oeis: A036239