A008867 - cp's OEIS frontend

A008867 Triangle of truncated triangular numbers: k-th term in n-th row is number of dots in hexagon of sides k, n-k, k, n-k, k, n-k.

n	a(n)
2	1
3	3
4	3
5	6
6	7
7	6
8	10
9	12
10	12
11	10
12	15
13	18
14	19
15	18
16	15
17	21
18	25
19	27
20	27
21	25
22	21
23	28
24	33
25	36
26	37
27	36
28	33
29	28
30	36
31	42
32	46
33	48
34	48
35	46
36	42
37	36
38	45
39	52
40	57
41	60
42	61
43	60
44	57
45	52
46	45
47	55
48	63
49	69
50	73
51	75
52	75
53	73
54	69
55	63
56	55
57	66
58	75
59	82
60	87
61	90
62	91
63	90
64	87
65	82
66	75
67	66
68	78
69	88
70	96
71	102
72	106
73	108
74	108
75	106
76	102
77	96
78	88
79	78

[1, 3, 3, 6, 7, 6, 10, 12, 12, 10, 15, 18, 19, 18, 15, 21, 25, 27, 27, 25, 21, 28, 33, 36, 37, 36, 33, 28, 36, 42, 46, 48, 48, 46, 42, 36, 45, 52, 57, 60, 61, 60, 57, 52, 45, 55, 63, 69, 73, 75, 75, 73, 69, 63, 55, 66, 75, 82, 87, 90, 91, 90, 87, 82, 75, 66, 78, 88, 96, 102, 106, 108, 108, 106, 102, 96, 88, 78]

cp's OEIS Frontend

A008867 Triangle of truncated triangular numbers: k-th term in n-th row is number of dots in hexagon of sides k, n-k, k, n-k, k, n-k.

Table of values

List of values

n	a(n)
2	1
3	3
4	3
5	6
6	7
7	6
8	10
9	12
10	12
11	10
12	15
13	18
14	19
15	18
16	15
17	21
18	25
19	27
20	27
21	25
22	21
23	28
24	33
25	36
26	37
27	36
28	33
29	28
30	36
31	42
32	46
33	48
34	48
35	46
36	42
37	36
38	45
39	52
40	57
41	60
42	61
43	60
44	57
45	52
46	45
47	55
48	63
49	69
50	73
51	75
52	75
53	73
54	69
55	63
56	55
57	66
58	75
59	82
60	87
61	90
62	91
63	90
64	87
65	82
66	75
67	66
68	78
69	88
70	96
71	102
72	106
73	108
74	108
75	106
76	102
77	96
78	88
79	78

n	a(n)
2	1
3	3
4	3
5	6
6	7
7	6
8	10
9	12
10	12
11	10
12	15
13	18
14	19
15	18
16	15
17	21
18	25
19	27
20	27
21	25
22	21
23	28
24	33
25	36
26	37
27	36
28	33
29	28
30	36
31	42
32	46
33	48
34	48
35	46
36	42
37	36
38	45
39	52
40	57
41	60
42	61
43	60
44	57
45	52
46	45
47	55
48	63
49	69
50	73
51	75
52	75
53	73
54	69
55	63
56	55
57	66
58	75
59	82
60	87
61	90
62	91
63	90
64	87
65	82
66	75
67	66
68	78
69	88
70	96
71	102
72	106
73	108
74	108
75	106
76	102
77	96
78	88
79	78

n	a(n)
2	1
3	3
4	3
5	6
6	7
7	6
8	10
9	12
10	12
11	10
12	15
13	18
14	19
15	18
16	15
17	21
18	25
19	27
20	27
21	25
22	21
23	28
24	33
25	36
26	37
27	36
28	33
29	28
30	36
31	42
32	46
33	48
34	48
35	46
36	42
37	36
38	45
39	52
40	57
41	60
42	61
43	60
44	57
45	52
46	45
47	55
48	63
49	69
50	73
51	75
52	75
53	73
54	69
55	63
56	55
57	66
58	75
59	82
60	87
61	90
62	91
63	90
64	87
65	82
66	75
67	66
68	78
69	88
70	96
71	102
72	106
73	108
74	108
75	106
76	102
77	96
78	88
79	78