Sort then Add, a(1)=3.

Terms

a(0) =3a(1) =6a(2) =12a(3) =24a(4) =48a(5) =96a(6) =165a(7) =321a(8) =444a(9) =888a(10) =1776a(11) =3453a(12) =6798a(13) =13587a(14) =27165a(15) =39732a(16) =63111a(17) =74247a(18) =98724a(19) =123513a(20) =235848a(21) =470436a(22) =504903a(23) =508362a(24) =531930a(25) =545289a(26) =790878a(27) =868767a(28) =1536555a(29) =2892111