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.

A257709 Numbers n such that T(n) + T(n+1) + ... + T(n+26) is a square, where T = A000217 (triangular numbers).

Table of values

n a(n)
1 8
2 14
3 39
4 53
5 103
6 112
7 206
8 264
9 509
10 647
11 1141
12 1230
13 2160
14 2734
15 5159
16 6525
17 11415
18 12296
19 21502
20 27184
21 51189
22 64711
23 113117
24 121838
25 212968
26 269214
27 506839
28 640693
29 1119863
30 1206192
31 2108286
32 2665064
33 5017309
34 6342327
35 11085621
36 11940190
37 20870000

List of values

[8, 14, 39, 53, 103, 112, 206, 264, 509, 647, 1141, 1230, 2160, 2734, 5159, 6525, 11415, 12296, 21502, 27184, 51189, 64711, 113117, 121838, 212968, 269214, 506839, 640693, 1119863, 1206192, 2108286, 2665064, 5017309, 6342327, 11085621, 11940190, 20870000]