Number of (weakly) superprimitive binary sequences of length n.

Terms

a(0) =1a(1) =2a(2) =2a(3) =6a(4) =12a(5) =28a(6) =54a(7) =118a(8) =230a(9) =490a(10) =968a(11) =1980a(12) =3978a(13) =8066a(14) =16100a(15) =32494a(16) =64994a(17) =130468a(18) =261000a(19) =523092a(20) =1046292a(21) =2094812a(22) =4189704a(23) =8383732a(24) =16768206a(25) =33545152a(26) =67090578a(27) =134199252a(28) =268399910a(29) =536834026