A065221 - cp's OEIS frontend

A065221 Fill a triangular array by rows by writing numbers 1 up to b(0), 1 up to b(1), etc., where b(n) are the pentagonal numbers. The final elements of the rows form a(n).

n	a(n)
0	1
1	2
2	5
3	4
4	9
5	3
6	10
7	18
8	5
9	15
10	26
11	3
12	16
13	30
14	45
15	10
16	27
17	45
18	64
19	14
20	35
21	57
22	80
23	12
24	37
25	63
26	90
27	1
28	30
29	60
30	91
31	123
32	11
33	45
34	80
35	116
36	153
37	15
38	54
39	94
40	135
41	177
42	10
43	54
44	99
45	145
46	192
47	240
48	42
49	92
50	143
51	195
52	248
53	15
54	70
55	126
56	183
57	241
58	300
59	30
60	91
61	153
62	216
63	280
64	345
65	35

[1, 2, 5, 4, 9, 3, 10, 18, 5, 15, 26, 3, 16, 30, 45, 10, 27, 45, 64, 14, 35, 57, 80, 12, 37, 63, 90, 1, 30, 60, 91, 123, 11, 45, 80, 116, 153, 15, 54, 94, 135, 177, 10, 54, 99, 145, 192, 240, 42, 92, 143, 195, 248, 15, 70, 126, 183, 241, 300, 30, 91, 153, 216, 280, 345, 35]

cp's OEIS Frontend

A065221 Fill a triangular array by rows by writing numbers 1 up to b(0), 1 up to b(1), etc., where b(n) are the pentagonal numbers. The final elements of the rows form a(n).

Table of values

List of values

n	a(n)
0	1
1	2
2	5
3	4
4	9
5	3
6	10
7	18
8	5
9	15
10	26
11	3
12	16
13	30
14	45
15	10
16	27
17	45
18	64
19	14
20	35
21	57
22	80
23	12
24	37
25	63
26	90
27	1
28	30
29	60
30	91
31	123
32	11
33	45
34	80
35	116
36	153
37	15
38	54
39	94
40	135
41	177
42	10
43	54
44	99
45	145
46	192
47	240
48	42
49	92
50	143
51	195
52	248
53	15
54	70
55	126
56	183
57	241
58	300
59	30
60	91
61	153
62	216
63	280
64	345
65	35

n	a(n)
0	1
1	2
2	5
3	4
4	9
5	3
6	10
7	18
8	5
9	15
10	26
11	3
12	16
13	30
14	45
15	10
16	27
17	45
18	64
19	14
20	35
21	57
22	80
23	12
24	37
25	63
26	90
27	1
28	30
29	60
30	91
31	123
32	11
33	45
34	80
35	116
36	153
37	15
38	54
39	94
40	135
41	177
42	10
43	54
44	99
45	145
46	192
47	240
48	42
49	92
50	143
51	195
52	248
53	15
54	70
55	126
56	183
57	241
58	300
59	30
60	91
61	153
62	216
63	280
64	345
65	35

n	a(n)
0	1
1	2
2	5
3	4
4	9
5	3
6	10
7	18
8	5
9	15
10	26
11	3
12	16
13	30
14	45
15	10
16	27
17	45
18	64
19	14
20	35
21	57
22	80
23	12
24	37
25	63
26	90
27	1
28	30
29	60
30	91
31	123
32	11
33	45
34	80
35	116
36	153
37	15
38	54
39	94
40	135
41	177
42	10
43	54
44	99
45	145
46	192
47	240
48	42
49	92
50	143
51	195
52	248
53	15
54	70
55	126
56	183
57	241
58	300
59	30
60	91
61	153
62	216
63	280
64	345
65	35