A055507 - cp's OEIS frontend

A055507 a(n) = Sum_{k=1..n} d(k)*d(n+1-k), where d(k) is number of positive divisors of k.

n	a(n)
1	1
2	4
3	8
4	14
5	20
6	28
7	37
8	44
9	58
10	64
11	80
12	86
13	108
14	108
15	136
16	134
17	169
18	160
19	198
20	192
21	236
22	216
23	276
24	246
25	310
26	288
27	348
28	310
29	400
30	344
31	433
32	396
33	474
34	408
35	544
36	450
37	564
38	512
39	614
40	522
41	688
42	560
43	716
44	638
45	756
46	636
47	860
48	676
49	859
50	772
51	926
52	758
53	1016
54	804
55	1032

[1, 4, 8, 14, 20, 28, 37, 44, 58, 64, 80, 86, 108, 108, 136, 134, 169, 160, 198, 192, 236, 216, 276, 246, 310, 288, 348, 310, 400, 344, 433, 396, 474, 408, 544, 450, 564, 512, 614, 522, 688, 560, 716, 638, 756, 636, 860, 676, 859, 772, 926, 758, 1016, 804, 1032]

cp's OEIS Frontend

A055507 a(n) = Sum_{k=1..n} d(k)*d(n+1-k), where d(k) is number of positive divisors of k.

Table of values

List of values