A273345 - cp's OEIS frontend

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.

n	a(n)
2	0
3	1
4	2
5	7
6	23
7	75
8	245
9	801
10	2622
11	8595
12	28215
13	92751
14	305304
15	1006207
16	3320071
17	10966741
18	36261414
19	120010103
20	397528422
21	1317860989
22	4372180109
23	14515485973
24	48222552640
25	160300772873
26	533176676911
27	1774359032599
28	5907894024527
29	19680307851415
30	65588436120988
31	218679463049627

[0, 1, 2, 7, 23, 75, 245, 801, 2622, 8595, 28215, 92751, 305304, 1006207, 3320071, 10966741, 36261414, 120010103, 397528422, 1317860989, 4372180109, 14515485973, 48222552640, 160300772873, 533176676911, 1774359032599, 5907894024527, 19680307851415, 65588436120988, 218679463049627]

cp's OEIS Frontend

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.

Table of values

List of values