A225339 - cp's OEIS frontend

A225339 Number of nX3 -1,1 arrays such that the sum over i=1..n,j=1..3 of i*x(i,j) is zero, the sum of x(i,j) is zero, and rows are nondecreasing (number of ways to distribute 3-across galley oarsmen left-right at n fore-aft positions so that there are no turning moments on the ship).

n	a(n)
1	0
2	0
3	0
4	6
5	0
6	0
7	0
8	410
9	0
10	0
11	0
12	47990
13	0
14	0
15	0
16	7030132
17	0
18	0
19	0
20	1163743294
21	0
22	0
23	0
24	208310242542
25	0
26	0
27	0
28	39371238885750
29	0
30	0
31	0
32	7745062224896578
33	0
34	0
35	0
36	1571069270148096124
37	0
38	0
39	0
40	326518765865030556374
41	0
42	0
43	0

[0, 0, 0, 6, 0, 0, 0, 410, 0, 0, 0, 47990, 0, 0, 0, 7030132, 0, 0, 0, 1163743294, 0, 0, 0, 208310242542, 0, 0, 0, 39371238885750, 0, 0, 0, 7745062224896578, 0, 0, 0, 1571069270148096124, 0, 0, 0, 326518765865030556374, 0, 0, 0]

cp's OEIS Frontend

A225339 Number of nX3 -1,1 arrays such that the sum over i=1..n,j=1..3 of i*x(i,j) is zero, the sum of x(i,j) is zero, and rows are nondecreasing (number of ways to distribute 3-across galley oarsmen left-right at n fore-aft positions so that there are no turning moments on the ship).

Table of values

List of values