a(n) = A102371(n) + n. Or, 2*A103745.

Terms

a(0) =0a(1) =2a(2) =4a(3) =10a(4) =16a(5) =34a(6) =68a(7) =130a(8) =256a(9) =514a(10) =1028a(11) =2058a(12) =4096a(13) =8194a(14) =16388a(15) =32770a(16) =65536a(17) =131074a(18) =262148a(19) =524298a(20) =1048592a(21) =2097154a(22) =4194308a(23) =8388610a(24) =16777216a(25) =33554434a(26) =67108868a(27) =134217738a(28) =268435456a(29) =536870914