The distinct values, in order of appearance, of A381087.

Terms

a(0) =2a(1) =1a(2) =6a(3) =31a(4) =64a(5) =331a(6) =814a(7) =1607a(8) =4107a(9) =5129a(10) =10283a(11) =12819a(12) =16163a(13) =40108a(14) =80313a(15) =100153a(16) =256379a(17) =1281895a(18) =2571143a(19) =3130008