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.

A072521 a(1) = 6 and then the smallest triangular numbers such that sum of two neighbors is also a triangular number.

Table of values

n a(n)
1 6
2 15
3 21
4 45
5 91
6 990
7 1711
8 365085
9 401856
10 713415
11 785631
12 1079715
13 1326006
14 2355535
15 2888406
16 5137615
17 5666661
18 5764710
19 9550635
20 9921285
21 10934826
22 19434495
23 21421785
24 23622501
25 42003195
26 46315500
27 82349361
28 146384605

List of values

[6, 15, 21, 45, 91, 990, 1711, 365085, 401856, 713415, 785631, 1079715, 1326006, 2355535, 2888406, 5137615, 5666661, 5764710, 9550635, 9921285, 10934826, 19434495, 21421785, 23622501, 42003195, 46315500, 82349361, 146384605]

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

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