a(n) = greatest k such that s(k) = n, where s = A026342.

Terms

a(0) =2a(1) =5a(2) =6a(3) =11a(4) =12a(5) =14a(6) =15a(7) =20a(8) =24a(9) =26a(10) =27a(11) =29a(12) =32a(13) =33a(14) =35a(15) =38a(16) =42a(17) =45a(18) =47a(19) =51a(20) =54a(21) =56a(22) =59a(23) =60a(24) =62a(25) =65a(26) =66a(27) =69a(28) =72a(29) =74