Number of 3-almost primes t such that 2^n < t <= 2^(n+1).

Terms

a(0) =0a(1) =0a(2) =1a(3) =1a(4) =5a(5) =6a(6) =17a(7) =30a(8) =65a(9) =131a(10) =257a(11) =536a(12) =1033a(13) =2132a(14) =4187a(15) =8370a(16) =16656a(17) =33123a(18) =65855a(19) =130460a(20) =259431a(21) =513737a(22) =1019223a(23) =2019783a(24) =4003071a(25) =7930375a(26) =15712418a(27) =31126184a(28) =61654062a(29) =122137206