A227316 - cp's OEIS frontend

A227316 a(n) = n(n+1) if n == 0 or 1 (mod 4), otherwise a(n) = n(n+1)/2.

n	a(n)
0	0
1	2
2	3
3	6
4	20
5	30
6	21
7	28
8	72
9	90
10	55
11	66
12	156
13	182
14	105
15	120
16	272
17	306
18	171
19	190
20	420
21	462
22	253
23	276
24	600
25	650
26	351
27	378
28	812
29	870
30	465
31	496
32	1056
33	1122
34	595
35	630
36	1332
37	1406
38	741
39	780
40	1640
41	1722
42	903
43	946
44	1980
45	2070
46	1081
47	1128

[0, 2, 3, 6, 20, 30, 21, 28, 72, 90, 55, 66, 156, 182, 105, 120, 272, 306, 171, 190, 420, 462, 253, 276, 600, 650, 351, 378, 812, 870, 465, 496, 1056, 1122, 595, 630, 1332, 1406, 741, 780, 1640, 1722, 903, 946, 1980, 2070, 1081, 1128]

cp's OEIS Frontend

A227316 a(n) = n(n+1) if n == 0 or 1 (mod 4), otherwise a(n) = n(n+1)/2.

Table of values

List of values