Number of (binary) bit strings of length n having at least one even length block of 0's followed by an even length block of 1's.

A065497

Number of (binary) bit strings of length n having at least one even length block of 0's followed by an even length block of 1's.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =2a(6) =7a(7) =16a(8) =40a(9) =92a(10) =209a(11) =468a(12) =1027a(13) =2242a(14) =4832a(15) =10360a(16) =22049a(17) =46694a(18) =98419a(19) =206588a(20) =432132a(21) =900980a(22) =1873297a(23) =3884904a(24) =8038295a(25) =16597478a(26) =34205700a(27) =70372728a(28) =144550977a(29) =296486538

External references