A346577 - cp's OEIS frontend

A346577 a(n) = (1/(3n)) Sum_{d|n} mu(n/d) * binomial(3*d,d).

n	a(n)
1	1
2	2
3	9
4	40
5	200
6	1026
7	5537
8	30624
9	173583
10	1001400
11	5864749
12	34768296
13	208267319
14	1258574114
15	7663720500
16	46976003712
17	289628805622
18	1794932293950
19	11175157356521
20	69864074596000
21	438403736543598
22	2760351027094298
23	17433869214973753
24	110420300844952992

[1, 2, 9, 40, 200, 1026, 5537, 30624, 173583, 1001400, 5864749, 34768296, 208267319, 1258574114, 7663720500, 46976003712, 289628805622, 1794932293950, 11175157356521, 69864074596000, 438403736543598, 2760351027094298, 17433869214973753, 110420300844952992]

cp's OEIS Frontend

A346577 a(n) = (1/(3n)) Sum_{d|n} mu(n/d) * binomial(3*d,d).

Table of values

List of values

cp's OEIS Frontend

A346577 a(n) = (1/(3*n)) * Sum_{d|n} mu(n/d) * binomial(3*d,d).

Table of values

List of values

A346577 a(n) = (1/(3n)) Sum_{d|n} mu(n/d) * binomial(3*d,d).