Number of integers in {1, 2, ..., 2^n} that are coprime to n.

Terms

a(0) =2a(1) =2a(2) =6a(3) =8a(4) =26a(5) =21a(6) =110a(7) =128a(8) =342a(9) =410a(10) =1862a(11) =1365a(12) =7562a(13) =7022a(14) =17477a(15) =32768a(16) =123362a(17) =87381a(18) =496694a(19) =419430a(20) =1198373a(21) =1906502a(22) =8023886a(23) =5592405a(24) =26843546a(25) =30973322a(26) =89478486a(27) =115043767a(28) =518358122a(29) =286331153