a(n) = Sum_{d|n} d*2^(n-d).

Terms

a(0) =1a(1) =4a(2) =7a(3) =20a(4) =21a(5) =94a(6) =71a(7) =328a(8) =457a(9) =1194a(10) =1035a(11) =7052a(12) =4109a(13) =17294a(14) =33807a(15) =83984a(16) =65553a(17) =389650a(18) =262163a(19) =1484820a(20) =1949717a(21) =4216854a(22) =4194327a(23) =29409304a(24) =22020121a(25) =67215386a(26) =119799835a(27) =350453788a(28) =268435485a(29) =1755807774