a(n) is the index of the n-th occurrence of 1 in A365203.

Terms

a(0) =1a(1) =14a(2) =53a(3) =109a(4) =221a(5) =445a(6) =893a(7) =1789a(8) =3581a(9) =7165a(10) =14333a(11) =28669a(12) =84530a(13) =295033a(14) =830369a(15) =1660741a(16) =4755764a(17) =10372048a(18) =28287409a(19) =56574821a(20) =153253317a(21) =323636916a(22) =848150626a(23) =2217511139a(24) =6534867338a(25) =20173498129a(26) =40346996261a(27) =120496984345