a(n) = A253174(2^n).

Terms

a(0) =1a(1) =0a(2) =0a(3) =2a(4) =4a(5) =2a(6) =10a(7) =12a(8) =34a(9) =54a(10) =128a(11) =214a(12) =444a(13) =768a(14) =1476a(15) =2730a(16) =5118a(17) =9768a(18) =18282a(19) =34682a(20) =65390a(21) =123772a(22) =236620