Number of unlabeled 3-element intersecting families (with not necessarily distinct sets) of an n-element set.

A055484

Number of unlabeled 3-element intersecting families (with not necessarily distinct sets) of an n-element set.

Terms

    a(0) =1a(1) =4a(2) =14a(3) =39a(4) =96a(5) =213a(6) =437a(7) =837a(8) =1520a(9) =2632a(10) =4380a(11) =7040a(12) =10979a(13) =16668a(14) =24716a(15) =35879a(16) =51104a(17) =71549a(18) =98625a(19) =134025a(20) =179782a(21) =238292a(22) =312386a(23) =405368a(24) =521083a(25) =663968a(26) =839140a(27) =1052439a(28) =1310534a(29) =1620985

External references