Number of (n+1)X(2+1) 0..1 arrays with no 2X2 subblock having zero or two 1s.

A251213

Number of (n+1)X(2+1) 0..1 arrays with no 2X2 subblock having zero or two 1s.

Terms

    a(0) =21a(1) =63a(2) =191a(3) =589a(4) =1807a(5) =5569a(6) =17119a(7) =52713a(8) =162143a(9) =499081a(10) =1535535a(11) =4725689a(12) =14541087a(13) =44748169a(14) =137696911a(15) =423732505a(16) =1303909887a(17) =4012461097a(18) =12347225455a(19) =37995389753a(20) =116920467935a(21) =359791896905

External references