a(n) is the number of elements in row n of A350605.

Terms

a(0) =1a(1) =3a(2) =7a(3) =15a(4) =30a(5) =60a(6) =119a(7) =237a(8) =472a(9) =940a(10) =1874a(11) =3740a(12) =7469a(13) =14918a(14) =29805a(15) =59561a(16) =119043a(17) =237966a(18) =475750a(19) =951213a(20) =1901981a(21) =3803271a(22) =7605468a(23) =15209251a(24) =30415896a(25) =60827703a(26) =121648985a(27) =243287862a(28) =486559789a(29) =973094453