Number of binary squares of length 2n that neither begin nor end with a shorter square.

Terms

a(0) =2a(1) =2a(2) =2a(3) =2a(4) =2a(5) =8a(6) =14a(7) =26a(8) =42a(9) =84a(10) =154a(11) =314a(12) =610a(13) =1220a(14) =2400a(15) =4836a(16) =9590a(17) =19220a(18) =38326a(19) =76684a(20) =153110a(21) =306294a(22) =612082a(23) =1224304a(24) =2447620a(25) =4895468a(26) =9789002a(27) =19578586a(28) =39153160a(29) =78307450