The number of increasing rooted identity trees.

Terms

a(0) =1a(1) =1a(2) =1a(3) =4a(4) =8a(5) =38a(6) =206a(7) =1200a(8) =7034a(9) =53012a(10) =465190a(11) =4072948a(12) =40967916a(13) =438348328a(14) =5113450320a(15) =63135973560a(16) =835727519000