A128918 - cp's OEIS frontend

A128918 a(n) = n(n+1)/2 if n is odd, otherwise (n-1)n/2 + 1.

n	a(n)
0	1
1	1
2	2
3	6
4	7
5	15
6	16
7	28
8	29
9	45
10	46
11	66
12	67
13	91
14	92
15	120
16	121
17	153
18	154
19	190
20	191
21	231
22	232
23	276
24	277
25	325
26	326
27	378
28	379
29	435
30	436
31	496
32	497
33	561
34	562
35	630
36	631
37	703
38	704
39	780
40	781
41	861
42	862
43	946
44	947
45	1035
46	1036
47	1128
48	1129
49	1225
50	1226
51	1326
52	1327
53	1431
54	1432
55	1540

[1, 1, 2, 6, 7, 15, 16, 28, 29, 45, 46, 66, 67, 91, 92, 120, 121, 153, 154, 190, 191, 231, 232, 276, 277, 325, 326, 378, 379, 435, 436, 496, 497, 561, 562, 630, 631, 703, 704, 780, 781, 861, 862, 946, 947, 1035, 1036, 1128, 1129, 1225, 1226, 1326, 1327, 1431, 1432, 1540]

cp's OEIS Frontend

A128918 a(n) = n(n+1)/2 if n is odd, otherwise (n-1)n/2 + 1.

Table of values

List of values

cp's OEIS Frontend

A128918 a(n) = n*(n+1)/2 if n is odd, otherwise (n-1)*n/2 + 1.

Table of values

List of values

A128918 a(n) = n(n+1)/2 if n is odd, otherwise (n-1)n/2 + 1.