a(n) = A048675(A285317(n)).

Terms

a(0) =18a(1) =36a(2) =19a(3) =8194a(4) =37a(5) =2147483648a(7) =8195a(8) =2056a(10) =67108868a(11) =16400a(12) =2057a(14) =2097184a(15) =67108869a(18) =16401a(21) =34359738376