A225343 - cp's OEIS frontend

A225343 Number of nX7 -1,1 arrays such that the sum over i=1..n,j=1..7 of i*x(i,j) is zero, the sum of x(i,j) is zero, and rows are nondecreasing (number of ways to distribute 7-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	22
5	0
6	0
7	0
8	25056
9	0
10	0
11	0
12	47084448
13	0
14	0
15	0
16	110202390974
17	0
18	0
19	0
20	291612344834026
21	0
22	0
23	0
24	834664320724959518
25	0
26	0
27	0
28	2522954614267660110474
29	0
30	0
31	0
32	7938386813443913197221460
33	0
34	0
35	0
36	25757964315025150183357153902
37	0
38	0
39	0

[0, 0, 0, 22, 0, 0, 0, 25056, 0, 0, 0, 47084448, 0, 0, 0, 110202390974, 0, 0, 0, 291612344834026, 0, 0, 0, 834664320724959518, 0, 0, 0, 2522954614267660110474, 0, 0, 0, 7938386813443913197221460, 0, 0, 0, 25757964315025150183357153902, 0, 0, 0]

cp's OEIS Frontend

A225343 Number of nX7 -1,1 arrays such that the sum over i=1..n,j=1..7 of i*x(i,j) is zero, the sum of x(i,j) is zero, and rows are nondecreasing (number of ways to distribute 7-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