A344720 - cp's OEIS frontend

A344720 a(n) = Sum_{k=1..n} (-1)^(k+1) * floor(n/k)^2.

n	a(n)
1	1
2	3
3	9
4	12
5	22
6	30
7	44
8	48
9	71
10	83
11	105
12	115
13	141
14	157
15	201
16	206
17	240
18	266
19	304
20	318
21	378
22	402
23	448
24	460
25	519
26	547
27	623
28	641
29	699
30	747
31	809
32	815
33	907
34	943
35	1035
36	1064
37	1138
38	1178
39	1286
40	1302
41	1384
42	1448
43	1534
44	1560
45	1710
46	1758
47	1852
48	1866
49	1977
50	2039
51	2179
52	2209
53	2315
54	2395
55	2535

[1, 3, 9, 12, 22, 30, 44, 48, 71, 83, 105, 115, 141, 157, 201, 206, 240, 266, 304, 318, 378, 402, 448, 460, 519, 547, 623, 641, 699, 747, 809, 815, 907, 943, 1035, 1064, 1138, 1178, 1286, 1302, 1384, 1448, 1534, 1560, 1710, 1758, 1852, 1866, 1977, 2039, 2179, 2209, 2315, 2395, 2535]

cp's OEIS Frontend

A344720 a(n) = Sum_{k=1..n} (-1)^(k+1) * floor(n/k)^2.

Table of values

List of values