a(n) = number of terms in s(n), where s(n) is defined in A096055.

Terms

a(0) =1a(1) =3a(2) =6a(3) =13a(4) =27a(5) =54a(6) =109a(7) =218a(8) =437a(9) =874a(10) =1749a(11) =3499a(12) =6998a(13) =13997a(14) =27994a(15) =55989a(16) =111978a(17) =223957a(18) =447915a(19) =895830a(20) =1791661a(21) =3583322a(22) =7166645a(23) =14333290a(24) =28666581a(25) =57333163a(26) =114666326a(27) =229332653a(28) =458665307a(29) =917330614