Number of length n 0..4 arrays with new values introduced in order from both ends.

A245159

Number of length n 0..4 arrays with new values introduced in order from both ends.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =9a(5) =23a(6) =65a(7) =199a(8) =654a(9) =2296a(10) =8568a(11) =33794a(12) =140039a(13) =605869a(14) =2718531a(15) =12564289a(16) =59419764a(17) =285878342a(18) =1392536354a(19) =6842206084a(20) =33819153429a(21) =167827213315a(22) =835048228437

External references