Number of arrays of the median of three adjacent elements of some length n+2 0..1 array.

Terms

a(0) =2a(1) =4a(2) =8a(3) =16a(4) =28a(5) =50a(6) =88a(7) =156a(8) =278a(9) =496a(10) =886a(11) =1582a(12) =2824a(13) =5040a(14) =8994a(15) =16050a(16) =28642a(17) =51114a(18) =91218a(19) =162788a(20) =290512a(21) =518448a(22) =925222a(23) =1651150a(24) =2946640a(25) =5258570a(26) =9384438a(27) =16747458a(28) =29887496a(29) =53337194