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.

A343771 Smallest k such that circle centered at the origin and with radius sqrt(k) passes through exactly 6*n integer points in the hexagonal lattice (see A004016).

Table of values

n a(n)
1 1
2 7
3 49
4 91
5 2401
6 637
7 117649
8 1729
9 8281
10 31213
11 282475249
12 12103
13 13841287201
14 1529437
15 405769
16 53599
17 33232930569601
18 157339
19 1628413597910449
20 593047
21 19882681
22 3672178237
23 3909821048582988049
24 375193
25 68574961
26 179936733613
27 2989441
28 29059303
29 459986536544739960976801
30 7709611

List of values

[1, 7, 49, 91, 2401, 637, 117649, 1729, 8281, 31213, 282475249, 12103, 13841287201, 1529437, 405769, 53599, 33232930569601, 157339, 1628413597910449, 593047, 19882681, 3672178237, 3909821048582988049, 375193, 68574961, 179936733613, 2989441, 29059303, 459986536544739960976801, 7709611]

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

Content is available under The OEIS End-User License Agreement.