Shifts left under COMPOSE transform with itself.

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =6a(5) =23a(6) =104a(7) =531a(8) =2982a(9) =18109a(10) =117545a(11) =808764a(12) =5862253a(13) =44553224a(14) =353713232a(15) =2924697019a(16) =25124481690a(17) =223768976093