a(n) = s(k), where k is the n-th number such that s(j)<s(k) for all j<k, where s = A026177.

Terms

a(0) =1a(1) =4a(2) =10a(3) =12a(4) =16a(5) =22a(6) =28a(7) =30a(8) =34a(9) =36a(10) =40a(11) =46a(12) =48a(13) =52a(14) =58a(15) =64a(16) =66a(17) =70a(18) =76a(19) =82a(20) =84a(21) =88a(22) =90a(23) =94a(24) =100a(25) =102a(26) =106a(27) =108a(28) =112a(29) =118