Number of nonisomorphic unordered triples of involutions on an n-set.

A362650

Number of nonisomorphic unordered triples of involutions on an n-set.

Terms

    a(0) =1a(1) =1a(2) =4a(3) =7a(4) =29a(5) =63a(6) =258a(7) =759a(8) =3263a(9) =12250a(10) =56330a(11) =250841a(12) =1235205a(13) =6113154a(14) =31941407a(15) =169613842a(16) =932670975a(17) =5223815423a(18) =30040926830a(19) =175918987173

External references