Number of sets of sets of lists.

Terms

a(0) =1a(1) =1a(2) =4a(3) =23a(4) =171a(5) =1552a(6) =16583a(7) =203443a(8) =2813660a(9) =43258011a(10) =731183365a(11) =13466814110a(12) =268270250977