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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.

A320853 Number of 7-element subsets of [n] whose sum is a triangular number.

Table of values

n a(n)
7 1
8 1
9 5
10 14
11 36
12 84
13 174
14 337
15 613
16 1058
17 1749
18 2787
19 4304
20 6463
21 9476
22 13598
23 19140
24 26486
25 36079
26 48461
27 64263
28 84209
29 109160
30 140100
31 178144
32 224578
33 280871
34 348655
35 429780
36 526341
37 640642
38 775262
39 933082
40 1117259
41 1331289
42 1579031
43 1864697
44 2192905

List of values

[1, 1, 5, 14, 36, 84, 174, 337, 613, 1058, 1749, 2787, 4304, 6463, 9476, 13598, 19140, 26486, 36079, 48461, 64263, 84209, 109160, 140100, 178144, 224578, 280871, 348655, 429780, 526341, 640642, 775262, 933082, 1117259, 1331289, 1579031, 1864697, 2192905]

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

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