a(n)=least k such that s(k)=n, where s=A030737.

Terms

a(0) =2a(1) =1a(2) =5a(3) =6a(4) =8a(5) =12a(6) =11a(7) =17a(8) =16a(9) =24a(10) =58a(11) =23a(12) =33a(13) =218a(14) =32a(15) =44a(16) =161a(17) =43a(18) =57a(19) =158a(20) =56a(21) =72a(22) =157a(23) =71a(24) =90a(25) =156a(26) =319a(27) =89a(28) =180a(29) =210