Sort then Add, a(1)=13.

Terms

a(0) =13a(1) =26a(2) =52a(3) =77a(4) =154a(5) =299a(6) =598a(7) =1187a(8) =2365a(9) =4721a(10) =5968a(11) =11657a(12) =23224a(13) =45458a(14) =90016a(15) =90185a(16) =91774a(17) =106553a(18) =120109a(19) =121238a(20) =233476a(21) =466943a(22) =811612a(23) =922880a(24) =945769a(25) =1402568a(26) =1527136a(27) =2650703a(28) =2674270a(29) =2898947