Number of (odd and even) split numbers (A036382) below 2^n.

Terms

a(0) =0a(1) =0a(2) =1a(3) =4a(4) =12a(5) =30a(6) =69a(7) =150a(8) =317a(9) =659a(10) =1361a(11) =2784a(12) =5686a(13) =11557a(14) =23445a(15) =47472a(16) =95991a(17) =193891a(18) =391266a(19) =788979a(20) =1589856a(21) =3201863a(22) =6445059a(23) =12967425a(24) =26080302a(25) =52434693a(26) =105386552a(27) =211751544a(28) =425359720a(29) =854245385