A309811 - cp's OEIS frontend

A309811 (sigma, tau)-superchampion numbers: numbers k for which there is a positive exponent e such that sigma(k)/(ktau(k)^e) >= sigma(j)/(jtau(j)^e) for all j >= 1, where tau(k) is the number of divisors of k (A000005) and sigma(k) is their sum (A000203).

n	a(n)
1	1
2	2
3	6
4	12
5	60
6	120
7	360
8	2520
9	5040
10	55440
11	720720
12	2162160
13	4324320
14	73513440
15	367567200
16	6983776800
17	160626866400
18	321253732800
19	9316358251200
20	288807105787200
21	2021649740510400
22	74801040398884800
23	224403121196654400
24	9200527969062830400
25	395622702669701707200

[1, 2, 6, 12, 60, 120, 360, 2520, 5040, 55440, 720720, 2162160, 4324320, 73513440, 367567200, 6983776800, 160626866400, 321253732800, 9316358251200, 288807105787200, 2021649740510400, 74801040398884800, 224403121196654400, 9200527969062830400, 395622702669701707200]

cp's OEIS Frontend

A309811 (sigma, tau)-superchampion numbers: numbers k for which there is a positive exponent e such that sigma(k)/(ktau(k)^e) >= sigma(j)/(jtau(j)^e) for all j >= 1, where tau(k) is the number of divisors of k (A000005) and sigma(k) is their sum (A000203).

Table of values

List of values

cp's OEIS Frontend

A309811 (sigma, tau)-superchampion numbers: numbers k for which there is a positive exponent e such that sigma(k)/(k*tau(k)^e) >= sigma(j)/(j*tau(j)^e) for all j >= 1, where tau(k) is the number of divisors of k (A000005) and sigma(k) is their sum (A000203).

Table of values

List of values

A309811 (sigma, tau)-superchampion numbers: numbers k for which there is a positive exponent e such that sigma(k)/(ktau(k)^e) >= sigma(j)/(jtau(j)^e) for all j >= 1, where tau(k) is the number of divisors of k (A000005) and sigma(k) is their sum (A000203).