a(n) = A372449(1+n) - A372449(n).

Terms

a(0) =3a(1) =5a(2) =11a(3) =21a(4) =40a(5) =81a(6) =161a(7) =324a(8) =647a(9) =1293a(10) =2587a(11) =5172a(12) =10346a(13) =20691a(14) =41380a(15) =82761a(16) =165521a(17) =331045a(18) =662088a(19) =1324177a(20) =2648354a(21) =5296706a(22) =10593414a(23) =21186826a(24) =42373653a(25) =84747305a(26) =169494608a(27) =338989217a(28) =677978434a(29) =1355956869