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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.

A137121 Numbers k such that k and k^2 use only the digits 3, 4, 5, 6 and 7.

Table of values

n a(n)
1 6
2 66
3 74
4 76
5 666
6 744
7 6666
8 6734
9 6756
10 7574
11 57756
12 66666
13 66756
14 67434
15 67656
16 74474
17 74476
18 577734
19 666666
20 666756
21 667334
22 667566
23 667656
24 745356
25 745476
26 6666666
27 6666756
28 6667566
29 6667656
30 6674334
31 6734744
32 6756734
33 7373376
34 7453574
35 7465744
36 7466434
37 7533576
38 7574744
39 66666666
40 66666756
41 66667566
42 66667656
43 66673334

List of values

[6, 66, 74, 76, 666, 744, 6666, 6734, 6756, 7574, 57756, 66666, 66756, 67434, 67656, 74474, 74476, 577734, 666666, 666756, 667334, 667566, 667656, 745356, 745476, 6666666, 6666756, 6667566, 6667656, 6674334, 6734744, 6756734, 7373376, 7453574, 7465744, 7466434, 7533576, 7574744, 66666666, 66666756, 66667566, 66667656, 66673334]

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

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