A324554 - cp's OEIS frontend

A324554 a(n) = the smallest number m such that gcd(tau(m), sigma(m)) = n where tau(k) = the number of the divisors of k (A000005) and sigma(k) = the sum of the divisors of k (A000203).

n	a(n)
1	1
2	3
3	18
4	6
5	648
6	20
7	2916
8	30
9	288
10	304
11	82944
12	60
13	36864
14	832
15	16200
16	168
17	5509980288
18	612
19	31719424
20	432
21	23328
22	44032
23	247669456896
24	420
25	9487368
26	258048
27	14112
28	2496
29	31581162962944
30	4176
31	26843545600
32	840
33	4064256
34	4390912
35	42693156
36	1980
37	151801324109824

[1, 3, 18, 6, 648, 20, 2916, 30, 288, 304, 82944, 60, 36864, 832, 16200, 168, 5509980288, 612, 31719424, 432, 23328, 44032, 247669456896, 420, 9487368, 258048, 14112, 2496, 31581162962944, 4176, 26843545600, 840, 4064256, 4390912, 42693156, 1980, 151801324109824]

cp's OEIS Frontend

A324554 a(n) = the smallest number m such that gcd(tau(m), sigma(m)) = n where tau(k) = the number of the divisors of k (A000005) and sigma(k) = the sum of the divisors of k (A000203).

Table of values

List of values