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.

A265580 Number of (unlabeled) loopless multigraphs with no isolated vertices such that the sum of the numbers of vertices and edges is n.

Table of values

n a(n)
0 1
1 0
2 0
3 1
4 1
5 2
6 4
7 7
8 13
9 27
10 54
11 112
12 243
13 538
14 1223
15 2875
16 6909
17 17052
18 43138
19 111686
20 295658
21 799684
22 2207356
23 6213391
24 17820961
25 52042771
26 154640528
27 467254731
28 1434837672
29 4475520062
30 14173115724
31 45548395180
32 148485883443
33 490831193397
34 1644581336531

List of values

[1, 0, 0, 1, 1, 2, 4, 7, 13, 27, 54, 112, 243, 538, 1223, 2875, 6909, 17052, 43138, 111686, 295658, 799684, 2207356, 6213391, 17820961, 52042771, 154640528, 467254731, 1434837672, 4475520062, 14173115724, 45548395180, 148485883443, 490831193397, 1644581336531]