cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A192709 Number of 9X2 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 <= 2*n^2 (number of collections of 9 zero-sum 2-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations).

Table of values

n a(n)
1 2
2 6
3 19
4 46
5 108
6 231
7 460
8 872
9 1581
10 2737
11 4607
12 7508
13 11904
14 18426
15 27989
16 41631
17 60856
18 87536
19 124153
20 173696
21 239976
22 327657
23 442880
24 592595
25 785351
26 1031659
27 1344609
28 1738831
29 2232241
30 2845802
31 3605355
32 4538949
33 5681318
34 7071215
35 8756412

List of values

[2, 6, 19, 46, 108, 231, 460, 872, 1581, 2737, 4607, 7508, 11904, 18426, 27989, 41631, 60856, 87536, 124153, 173696, 239976, 327657, 442880, 592595, 785351, 1031659, 1344609, 1738831, 2232241, 2845802, 3605355, 4538949, 5681318, 7071215, 8756412]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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