A110422 - cp's OEIS frontend

A110422 a(n) = sum( (-1)^(r+1)(n-r)r, r = 1..floor(n/2) ).

n	a(n)
2	1
3	2
4	-1
5	-2
6	6
7	8
8	-6
9	-8
10	15
11	18
12	-15
13	-18
14	28
15	32
16	-28
17	-32
18	45
19	50
20	-45
21	-50
22	66
23	72
24	-66
25	-72
26	91
27	98
28	-91
29	-98
30	120
31	128
32	-120
33	-128
34	153
35	162
36	-153
37	-162
38	190
39	200
40	-190
41	-200
42	231
43	242
44	-231
45	-242
46	276
47	288
48	-276
49	-288
50	325
51	338
52	-325
53	-338
54	378
55	392
56	-378
57	-392
58	435
59	450
60	-435
61	-450
62	496
63	512
64	-496
65	-512
66	561

[1, 2, -1, -2, 6, 8, -6, -8, 15, 18, -15, -18, 28, 32, -28, -32, 45, 50, -45, -50, 66, 72, -66, -72, 91, 98, -91, -98, 120, 128, -120, -128, 153, 162, -153, -162, 190, 200, -190, -200, 231, 242, -231, -242, 276, 288, -276, -288, 325, 338, -325, -338, 378, 392, -378, -392, 435, 450, -435, -450, 496, 512, -496, -512, 561]

cp's OEIS Frontend

A110422 a(n) = sum( (-1)^(r+1)(n-r)r, r = 1..floor(n/2) ).

Table of values

List of values

cp's OEIS Frontend

A110422 a(n) = sum( (-1)^(r+1)*(n-r)*r, r = 1..floor(n/2) ).

Table of values

List of values

A110422 a(n) = sum( (-1)^(r+1)(n-r)r, r = 1..floor(n/2) ).