Left inverse of A274647.

Terms

a(0) =0a(1) =1a(2) =4a(3) =2a(4) =203a(5) =2597a(6) =3a(7) =5a(8) =16a(9) =14a(10) =12a(11) =10a(12) =8a(13) =6a(14) =97a(15) =15546a(16) =243575589a(17) =404450a(18) =23a(19) =404448a(20) =7a(21) =9a(22) =11a(23) =13a(24) =15a(25) =17a(26) =56a(27) =54a(28) =52a(29) =50