Number of levels in all bargraphs having semiperimeter n (n>=2). A level in a bargraph is a maximal sequence of two or more adjacent horizontal steps; it is preceded and followed by either an up step or a down step.
A273345
Number of levels in all bargraphs having semiperimeter n (n>=2). A level in a bargraph is a maximal sequence of two or more adjacent horizontal steps; it is preceded and followed by either an up step or a down step.
Terms
- a(0) =0a(1) =1a(2) =2a(3) =7a(4) =23a(5) =75a(6) =245a(7) =801a(8) =2622a(9) =8595a(10) =28215a(11) =92751a(12) =305304a(13) =1006207a(14) =3320071a(15) =10966741a(16) =36261414a(17) =120010103a(18) =397528422a(19) =1317860989a(20) =4372180109a(21) =14515485973a(22) =48222552640a(23) =160300772873a(24) =533176676911
External references
- oeis: A273345