A061726 - cp's OEIS frontend

A061726 If n-th triangular number (A000217(n)) is odd, multiply it by 4; if even, multiply it by 5.

n	a(n)
1	4
2	12
3	30
4	50
5	60
6	84
7	140
8	180
9	180
10	220
11	330
12	390
13	364
14	420
15	600
16	680
17	612
18	684
19	950
20	1050
21	924
22	1012
23	1380
24	1500
25	1300
26	1404
27	1890
28	2030
29	1740
30	1860
31	2480
32	2640
33	2244
34	2380
35	3150
36	3330
37	2812
38	2964
39	3900
40	4100
41	3444
42	3612
43	4730
44	4950
45	4140
46	4324
47	5640

[4, 12, 30, 50, 60, 84, 140, 180, 180, 220, 330, 390, 364, 420, 600, 680, 612, 684, 950, 1050, 924, 1012, 1380, 1500, 1300, 1404, 1890, 2030, 1740, 1860, 2480, 2640, 2244, 2380, 3150, 3330, 2812, 2964, 3900, 4100, 3444, 3612, 4730, 4950, 4140, 4324, 5640]

cp's OEIS Frontend

A061726 If n-th triangular number (A000217(n)) is odd, multiply it by 4; if even, multiply it by 5.

Table of values

List of values