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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.

A078262 Sum of the forward and reverse concatenations of 1 to n.

Table of values

n a(n)
1 2
2 33
3 444
4 5555
5 66666
6 777777
7 8888888
8 99999999
9 1111111110
10 23333333231
11 2345555545332
12 244567776755433
13 25466789897765534
14 2647689001998775635
15 274869910212099785736
16 28497092031222200795837
17 2950719304132232301805938
18 305172940514233242402816039

List of values

[2, 33, 444, 5555, 66666, 777777, 8888888, 99999999, 1111111110, 23333333231, 2345555545332, 244567776755433, 25466789897765534, 2647689001998775635, 274869910212099785736, 28497092031222200795837, 2950719304132232301805938, 305172940514233242402816039]

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

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