Number of unlabeled 7-ary cacti having n polygons.

A054369

Number of unlabeled 7-ary cacti having n polygons.

Terms

    a(0) =1a(1) =1a(2) =7a(3) =28a(4) =231a(5) =2100a(6) =23884a(7) =285390a(8) =3626295a(9) =47813815a(10) =650367788a(11) =9066061200a(12) =128987761308

External references