A336489 - cp's OEIS frontend

A336489 Consider the figure made up of a row of n adjacent congruent rectangles, with diagonals of all possible rectangles drawn; a(n) = number of interior vertices where exactly three lines cross.

n	a(n)
1	0
2	1
3	2
4	8
5	18
6	32
7	50
8	102
9	126
10	198
11	286
12	390
13	510
14	742
15	878
16	1130
17	1414
18	1770
19	2166
20	2778
21	3186
22	3858
23	4594
24	5342
25	6146
26	7342
27	8294
28	9662
29	11134
30	12710
31	14390
32	16582
33	18226
34	20518
35	22946
36	25662
37	28530
38	32270
39	35250
40	38862
41	42650
42	46614
43	50754
44	55990
45	60730

[0, 1, 2, 8, 18, 32, 50, 102, 126, 198, 286, 390, 510, 742, 878, 1130, 1414, 1770, 2166, 2778, 3186, 3858, 4594, 5342, 6146, 7342, 8294, 9662, 11134, 12710, 14390, 16582, 18226, 20518, 22946, 25662, 28530, 32270, 35250, 38862, 42650, 46614, 50754, 55990, 60730]

cp's OEIS Frontend

A336489 Consider the figure made up of a row of n adjacent congruent rectangles, with diagonals of all possible rectangles drawn; a(n) = number of interior vertices where exactly three lines cross.

Table of values

List of values