a(n) is the position of A051451(n) in A025487.

Terms

a(0) =1a(1) =2a(2) =4a(3) =6a(4) =13a(5) =29a(6) =36a(7) =55a(8) =112a(9) =223a(10) =264a(11) =514a(12) =956a(13) =1749a(14) =2345a(15) =2847a(16) =5005a(17) =8567a(18) =9507a(19) =16073a(20) =26792a(21) =43730a(22) =70482a(23) =88969a(24) =140871a(25) =221370a(26) =342958a(27) =368588a(28) =565510a(29) =859401