a(n) is the position of the first occurrence of n in A323077.

Terms

a(0) =1a(1) =4a(2) =8a(3) =16a(4) =27a(5) =54a(6) =81a(7) =162a(8) =243a(9) =486a(10) =729a(11) =1458a(12) =2187a(13) =4374a(14) =6561a(15) =12005a(16) =16807a(17) =33614a(18) =50421a(19) =84035a(20) =117649a(21) =235298a(22) =352947a(23) =588245a(24) =823543a(25) =1647086a(26) =2470629a(27) =4117715a(28) =5764801a(29) =11529602