A192691 - cp's OEIS frontend

A192691 Number of 1X4 integer matrices with each row summing to zero, row elements in nondecreasing order, rows in lexicographically nondecreasing order, and the sum of squares of the elements <= 2n^2 (number of collections of 1 zero-sum 4-vectors with total modulus squared not more than 2n^2, ignoring vector and component permutations).

n	a(n)
1	2
2	6
3	15
4	26
5	45
6	72
7	105
8	150
9	206
10	273
11	353
12	446
13	560
14	687
15	834
16	998
17	1182
18	1388
19	1618
20	1875
21	2156
22	2463
23	2797
24	3151
25	3551
26	3978
27	4434
28	4923
29	5448
30	6009
31	6604
32	7243
33	7925
34	8639
35	9404
36	10198
37	11051
38	11943
39	12887
40	13873
41	14909
42	16001
43	17135
44	18332
45	19584

[2, 6, 15, 26, 45, 72, 105, 150, 206, 273, 353, 446, 560, 687, 834, 998, 1182, 1388, 1618, 1875, 2156, 2463, 2797, 3151, 3551, 3978, 4434, 4923, 5448, 6009, 6604, 7243, 7925, 8639, 9404, 10198, 11051, 11943, 12887, 13873, 14909, 16001, 17135, 18332, 19584]

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Table of values

List of values