A160399 - cp's OEIS frontend

A160399 a(n) = Sum_{k=1..n} binomial(n,k) * d(k), where d(k) = the number of positive divisors of k.

n	a(n)
1	1
2	4
3	11
4	27
5	62
6	137
7	296
8	630
9	1326
10	2768
11	5744
12	11867
13	24429
14	50135
15	102627
16	209641
17	427518
18	870579
19	1770536
20	3596614
21	7298397
22	14796658
23	29974913
24	60681233
25	122767148
26	248232863
27	501648844
28	1013257334
29	2045684971

[1, 4, 11, 27, 62, 137, 296, 630, 1326, 2768, 5744, 11867, 24429, 50135, 102627, 209641, 427518, 870579, 1770536, 3596614, 7298397, 14796658, 29974913, 60681233, 122767148, 248232863, 501648844, 1013257334, 2045684971]

cp's OEIS Frontend

A160399 a(n) = Sum_{k=1..n} binomial(n,k) * d(k), where d(k) = the number of positive divisors of k.

Table of values

List of values